If you plan on designing a DIY solar setup for your home, shed, or RV, the heart of the system will be the battery bank

LiFePO4 battery banks in parallel

If you plan on designing a DIY solar setup for your home, shed, or RV, the heart of the system will be the battery bank. While there are several chemistries to choose from, LiFePO4 is often the best choice for home energy systems for several reasons. At some point you will be asking yourself, “How do you safely and efficiently connect multiple LiFePO4 battery banks in parallel?” &nbsp;(You can also check out our full guide on <a href="https://cellsaviors.com/blog/parallel-lithium-batteries">how to wire lithium batteries in parallel to increase amperage</a>.)&nbsp;Wiring LiFePO4 batteries in parallel is simple. All you have to do is connect all the positive terminals together and all of the negative terminals together. There is, however, some nuance involved depending on how much current your running, and how balanced your parallel connections are.In this article, we’ll go over all the ways you can wire LeFePO4 batteries in parallel, and we will explain how to maintain a proper balance of current when doing so.&nbsp;Why Choose LiFePO4 for Your Home Energy System? Cycle Life Lithium iron phosphate batteries have several different properties compared to the traditional NMC chemistry that most lithium-ion batteries use. And the most important one is the cycle life.Your typical NMC lithium-ion battery can be recharged 500–800 times before it's considered end of life, at which point it only holds 80% of the capacity that it used to, and its internal resistance will have by then increased dramatically.Lithium iron phosphate batteries, on the other hand, can last 2,000, 3,000, or even 4,000 cycles, depending on the quality of the cells and how you use them. Voltage Range for Home Energy Applications Also, they have a more ideal voltage range for home energy applications, because most of the equipment that's used for home energy solutions — such as inverters, charge controllers, etc. — are made for either a 12 or 24-volt voltage range.Systems and their components exist outside of those values, but most of the time, home energy systems are either going to be in the 12 or 24-volt range. NMC in 24-Volt Systems It's relatively easy to make something 24-volt compatible using NMC cells because you can just put 7 in series. The full charge voltage would be 29.4 volts, the nominal voltage would be 3.7 times 7, which would be 25.9 volts, and the dead voltage would be about 2.8 times 7 for about 19.6 volts.So you've got around a 20 to 30-volt range with a 7S NMC lithium-ion battery. And because most 24-volt devices can work well within and even beyond that range, you won't have any problems. NMC in 12-Volt Systems But when you try to make 12 volts, you run into an issue. If you want to make 12 volts with NMC cells, you can try to put either 3 or 4 in series. Let's do both:<ul><li>3 times 3.7 is 11.1 volts, so that's close enough to 12 volts for the nominal voltage. But if you do the dead voltage around 2.8 times 3, you're down to 8.4 volts. Even if you raise your cutoff voltage to 3 volts, you're down to 9 volts. That's too low to operate a 12-volt system. </li><li>So let's try to add another cell in series. For 4S, we have a nominal voltage of 3.7 times 4. Well, that's 14.8. That's a little higher than 12 volts. It'd probably be okay. Most equipment that's made to run at 12 volts will cut off around 15 volts or something like that on the high end. So it would probably be okay. </li></ul>But remember, that's just the nominal voltage. That means you're losing all the capacity north of nominal voltage, because 4.2 times 4 is 16.8. That's way too high for any 12-volt system. LFP in 12-Volt Systems But we can compare that now to LFP. With LFP, you have a 3.7-volt maximum voltage and a 3.2-volt nominal voltage.So 3.7 times 4, and we get 14.8. That's the max charge voltage. That's about what an alternator puts out when it's charging your car, which is a 12-volt lead-acid battery.And then when those batteries are dead, around 2.8 volts, multiply that by 4, and we have 11.2. That's still well within the acceptable operating range of a 12-volt system. Why LFP is Ideal for Home Energy Storage So because of the many, many more cycles and the much, much better voltage range, LFP is definitely the way to go for home storage systems.The one big drawback — pun intended — of LFP is that they're much lower energy density than NMC. So they're going to be larger. They're going to have more volume. They're going to be heavier compared to an equal-capacity NMC battery.But the thing is, for home storage, that doesn't matter. That matters if you're doing an e-bike battery or something like that, that has to be small, compact, and lightweight. At that point, you would want to use NMC because it's got the best energy density.But for home energy storage, it doesn't have to be ultra-compact. And these batteries are still much more light, much more compact, and much more energy dense than the lead-acid batteries that they replace. And they last a whole lot longer. So for those reasons, LFP is definitely the best way to go for home energy storage.<h2>Wiring LiFePO4 Battery Banks in Parallel</h2> Can One 100Ah LFP Battery Power a House? You might think if you're just starting out that you could get a single 100 amp hour 12-volt LFP battery and run your entire house, but just not for very long. That's not the case because most of these batteries have around a 200 amp discharge current limit. At a nominal voltage of 12.8 volts, 200 amps is just 2.56 kilowatts.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/png&quot;,&quot;filename&quot;:&quot;image.png&quot;,&quot;filesize&quot;:716809,&quot;height&quot;:970,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/OfiPLxGnTdeciGv7aJedFujOFs1dE0dmqQG5qxou.png&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/OfiPLxGnTdeciGv7aJedFujOFs1dE0dmqQG5qxou.png&quot;,&quot;width&quot;:2000}" data-trix-content-type="image/png" data-trix-attributes="{&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--png"><a href="https://admin.cellsaviors.com/storage/OfiPLxGnTdeciGv7aJedFujOFs1dE0dmqQG5qxou.png"><img src="https://admin.cellsaviors.com/storage/OfiPLxGnTdeciGv7aJedFujOFs1dE0dmqQG5qxou.png" width="2000" height="970"><figcaption class="attachment__caption">image.png 700.01 KB</figcaption></a></figure>The average American household uses somewhere between 4 and 7 kilowatts of energy at any given point. It can go lower or higher than that, but that's a decent average to consider. So that means you have to put LFP batteries in parallel for increased current, even if you don't want the added capacity that comes along with that. Wiring Batteries in Parallel: Two Methods There's two ways to wire batteries in parallel. You can do a simple daisy chain setup where one battery connects to the next battery in a row, and at one end of the row you'll have your positive and negative connections for energy to go in and out of the battery bank.Or you can do a star topology where all the batteries have the same length cables and connect to some central point. The Daisy Chain Arrangement The first one we'll cover is the daisy chain arrangement. This can work fine in many applications as long as you consider:<ul><li>the amount of current that you're going to draw, </li><li>the amount of current that each battery can support, and </li><li>the amount of current that your parallel connections can take. </li></ul>For example, if you have three 100 amp hour LiFePO4 batteries wired in parallel and they can each do 200 amps of current, that means the battery bank as a whole can do 600 amps of current.Your series connections are extremely important when you're wiring LiFePO4 battery banks in parallel. If the cables can only do 200 amps each and you put a 600 amp load on the battery, in an ideal world each battery would see 200 amps of the load because it would be split three ways.But remember they're all connected with the same 200 amp cable, and the electrons will take the path of least resistance. So if you have one long cable that's the same width the whole way down, the further and further you go, the higher and higher the resistance.That means even if all of your LiFePO4 battery banks have the same resistance and they can all handle a very high current, if you have them in a daisy chain and you draw a high current from them, the battery closest to the terminals — the output — will see most of the load.It will be somewhat split amongst the batteries, but most of the load will be seen by that first battery. Its voltage will drop more than the batteries at the end because the batteries at the end are seeing a much lighter load.And then in an instant, right then and there, the batteries at the end will be charging the batteries closer to the terminals. This happens very quickly and ultimately isn't dangerous, but it does reduce the life of the batteries. Improving the Daisy Chain Setup The best way to wire LiFePO4 battery banks in parallel, if you're going to do the daisy chain method, would be to use more and more cable to connect each battery further and further down the line.So you might use one positive and one negative cable for the first two batteries. And then for the next two batteries, you can use two positive and two negative cables. And then for the next two batteries, use four positive and four negative cables.That way, you don't have to use so many cables the whole way down, and doing this will help even out the resistance.If you don't want to do all that, then just make sure to keep your load at about half of your total current. So if you can support 600 amps, do 300 amps on the battery bank and it'll be just fine. But it will have a slightly reduced life because of that. The Star Topology Arrangement The other way is by organizing them in a star topology. If you have all of your batteries surrounding an area where you want to put your terminals, you can simply use the same length cable to connect all of those batteries to that common terminal.This will make a circular-shaped setup, but it makes it extremely easy to get balancing just right.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/png&quot;,&quot;filename&quot;:&quot;batteryRing.png&quot;,&quot;filesize&quot;:1449231,&quot;height&quot;:2688,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/qC7FHSoGnZHqTyAd0ZbbCdtlRdfwRGO4xQmR6KQy.png&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/qC7FHSoGnZHqTyAd0ZbbCdtlRdfwRGO4xQmR6KQy.png&quot;,&quot;width&quot;:3780}" data-trix-content-type="image/png" data-trix-attributes="{&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--png"><a href="https://admin.cellsaviors.com/storage/qC7FHSoGnZHqTyAd0ZbbCdtlRdfwRGO4xQmR6KQy.png"><img src="https://admin.cellsaviors.com/storage/qC7FHSoGnZHqTyAd0ZbbCdtlRdfwRGO4xQmR6KQy.png" width="3780" height="2688"><figcaption class="attachment__caption">batteryRing.png 1.38 MB</figcaption></a></figure>You could obviously arrange the batteries any way you want and just make sure you use the same length cable for each battery. But you'll end up with a bundle of cables somewhere or in multiple places if you do that — which is why I suggested the radial arrangement for connecting LiFePO4 battery banks in parallel while maintaining the balance of the parallel connections.<h2>Conclusion</h2>Whether you're expanding your DIY solar storage, setting up a battery backup generator, or preparing for the next power outage, understanding how to wire LiFePO4 battery banks in parallel is key.With the right wiring, proper charging using MPPT controllers,&nbsp; (learn more about the difference between <a href="https://cellsaviors.com/blog/mppt-pwm-solar-charge-controller">PWM and MPPT solar charge controllers</a>) , reliable equipment like Victron inverters, and smart safety practices, your battery bank will deliver dependable, long-lasting performance for your home, shed, RV, or off-grid retreat.

LiFePO4 Battery Banks in Parallel

This regulator board is really great with a power switch right there, but you can also control the output with the screen. 

Regulator board

<h2>Regulator Board Overview</h2>This regulator board is really great. It's a constant current buck converter. Here's the input, here's the output, and here's the connections for the screen. Even though the connectors are the same for the screen, it's really easy to remember how to hook it up because the left side on the screen goes to the left side on the board, and the right side on the screen goes to the right side on the board.There’s a power switch right there, but you can also control the output with the screen. You can use any connections you want. You can make a male and female like this and use it for the output of the input.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/jpeg&quot;,&quot;filename&quot;:&quot;微信图片_20250428100434.jpg&quot;,&quot;filesize&quot;:125204,&quot;height&quot;:720,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/rcxTbNkElCCkmLyLs7lCahYbpKQB5RyOPWg5xbxO.jpg&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/rcxTbNkElCCkmLyLs7lCahYbpKQB5RyOPWg5xbxO.jpg&quot;,&quot;width&quot;:1280}" data-trix-content-type="image/jpeg" data-trix-attributes="{&quot;caption&quot;:&quot;Regulator board&quot;,&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--jpg"><a href="https://admin.cellsaviors.com/storage/rcxTbNkElCCkmLyLs7lCahYbpKQB5RyOPWg5xbxO.jpg"><img src="https://admin.cellsaviors.com/storage/rcxTbNkElCCkmLyLs7lCahYbpKQB5RyOPWg5xbxO.jpg" width="1280" height="720"><figcaption class="attachment__caption attachment__caption--edited">Regulator board</figcaption></a></figure><h2>Input Voltage and Capacitors</h2>On the Amazon page, it says a max input of 50 volts. It depends on the listing you're looking at and which part of the listing you're looking at. But I can tell you it has 63-volt input capacitors and 63-volt output capacitors. I haven't checked the tolerances of the other chips, but I've run this reliably with a 54-volt input. Actually, I stepped that up to 55 recently, and it's been running like that fine for weeks.As far as the output, the maximum of that output is going to be about a volt and a half lower than whatever the input is, but it still has its own maximum. I believe that's 51 volts.<h2>Fan and Thermal Protection</h2>It has a fan right here, and this fan is really well done. What's special about the fan? Nothing. It's a cheap, low voltage, low current fan. It's the control system they're using that's nice. The fan only kicks on when it really needs to, and if that fan's running, this thing is not going to be hot – maybe just warm to the touch. You'd have to put it in extreme circumstances like maxing out the output current at 20 amps while having like a 40-volt difference between the input and the output for this thing to struggle. And if it does, it will cut off. I haven't had these burn up on their own. The only way I've broken these is by damaging the board, hooking it up backwards, or doing something else stupid. This thing works just as good as it says it will.<h2>Curious Connections and Screen Functionality</h2>It also has these curious connections here. I’ve probed them while it’s running and while I'm changing settings. Some of these pins seem to be voltages that are proportional to whatever current and voltage that you set it to. I’ll have to look into that more later.Regardless of those pins and what they might do, there is opportunity here because I do believe the screen is I²C. If it's not I²C, it's some sort of basic digital protocol. So this cheap, low-quality screen could easily be replaced, and it's the only bad thing I have to say about this regulator.<h2>Usability and Ease of Integration</h2>Well, there is one more bad thing I have to say about this regulator: no one knows how good it is. Even if you know how good it is, you have to do a bunch of stuff— not a lot of stuff, but you have to do stuff before you can use it. You’ve got to solder up some connectors or have something that you can wire it into. If you’re wiring it into something, you don’t necessarily need it to be a variable thing, which this is and does well. So you’re going to need to make some sort of connector that you can plug in and unplug. There are all kinds of steps and processes; there will always be steps and processes to use stuff. There’s nothing wrong with that, but to lower the barrier to entry, we want to reduce those steps to as few as possible.So, I made this case for it. It has flush mount male XT60 inputs and flush mount female XT60 outputs.<h2>Personal Experience and Reliability</h2>I really, really love this regulator. I own several of them—I think five, not including the testing ones. They work really, really well. They’re very reliable and have a very wide voltage range. I use them all the time. They are very, very good.So, I'm going to make a charger—a custom case with this regulator, screen, and these ports all installed in it. I'm going to sell it for a profit, but that's not what this article/video is about. This is about this regulator board, which is really, really good.<h2>Applications and Performance</h2> Powering Lower Voltage Devices What can you do with this regulator board? Well, if your time is important to you, a list of what you can't do with it would be a lot shorter. But let's just talk about what it can do. The most obvious thing to do with a <a href="https://cellsaviors.com/blog/buck-boost-converters">buck converter</a> is to power a lower voltage device with a higher voltage input. Here I've got a 30.8-volt input from an AC-to-DC power supply. It's actually a 24-volt power supply that has a potentiometer on it. I turned it all the way up so I can get the highest voltage possible—that ends up being 30.8 volts, as you can see.So, I have this 12-volt LED strip. You can run it a little bit over 12 volts if you want some extra brightness at the expense of a lower operational lifespan. But you don't want to go too far; you definitely don't want to put 30 volts into it. It won't last very long and it'll get very hot. You can see the output voltage here is set to 14.46 volts. Basically, 14.5 volts is the highest voltage that you want to run 12-volt lights. I've just noticed that as a rule of thumb—any higher than that and you're just not getting the brightness that you deserve for the power that you're putting into it. Dimming and Cutting LED Strips As you can see, it works just fine, and I can control the voltage here so that means I can control the brightness. This is ideal for these lights. These particular LEDs on this strip, at 14.46 volts, draw about 0.91 amps, which is 13.3 watts. Actually, I'm curious—let's cut the LED strip at one of the approved cutting locations because this is a certain amount of LEDs in series and you can't cut it at any one. There we go. Now we're powering it with the normal acceptable overvoltage. When you're running them higher than 12 volts, you will get a little more heat and a slightly lower lifespan, but it's a decent brightness increase. In my opinion, it's worth it because these are really cheap, and even running them like this, I haven't had any fail yet. I just know they will soon, and I've been using them for a long time. Sensitivity at Low Voltage I've got this reasonable size strip here to donate to science because I don't want to ruin my whole thing. Let's see what happens if we didn't have this regulator in between this 30-volt power supply and this strip. One thing I'd like to mention—the LEDs are definitely on and they're being powered by this, but it's showing no current. While I've found that this is reasonably accurate over its full range, it has very little sensitivity at the low, low, low end of the spectrum. So you can't really use this thing to measure milliamps, at least single milliamps very accurately. But in the tens of milliamps and ups, you're good to go for most applications.So what happens if we increase the voltage? Let's take it to 17 volts. It's probably enough to register now. Yep, so it's reading 4 milliamps at 17 volts. It's obviously more than that. So it's not very accurate at the low end. We're doing 0.73 watts, according to this—probably around a watt. Okay, so let's increase the voltage more. Now we're at 34 volts, and there it went.<h2>Maximum Input and Protection Mechanisms</h2>If you use this regulator between any power supply that's like 13 volts or higher and less than 55 volts (that's the highest I've taken this to on the input), you can run 12-volt devices like these LEDs safely within 20 amps. This thing really can do 20 amps, and as you can see, it does its protection as well. Because in the instant that those burned up, they became a dead short, which drew like a ton of current and dropped the voltage, this went into protection. To pull it out of protection, obviously you want to disconnect the load and then just press the button once or twice—press it once to get it back on and press it again to turn on the output.I noticed that nothing's plugged into the output and it's still running protection. Maybe something's wrong. I think we can just turn it off and then turn it back on again. There we go. I've had this recovered from protection without having to do that. That's new to me right now, but everything seems to be just fine.<h2>Alternative Uses: Multimeter Functionality</h2>They can even be used as a basic multimeter. I don't really recommend doing this, but it can get you out of a pinch or be helpful in some situations. All you have to do is set the output voltage to something that you know, absolutely know for sure, is higher than the voltage you’re trying to measure, then set the current to zero. When you do that, the voltage will fall to whatever it is and will pass no current. So, for example, we can plug into this 7S battery, and we can see that it's at 24.93 volts. Remember, this is not a multimeter, so you cannot reverse those and have things be okay if you're trying to use this to take a voltage measurement. But I just did, and we know this is at around 25 volts. So now I'm going to unplug it.Now I'm going to set it to a charge voltage; the batteries are around 25 volts, so anything above that will work. Let's do 27—that's close enough. You can set it to... those are MH1s, it's just 1S, sorry, 1P7S. So let's just set it to 2 amps. There we go. Then, let’s read—oops, I pressed the wrong button. I do that all the time. Let's read amps. There we go. Then we plug it in, and you can see this regulator board drops its output voltage to whatever it has to drop it to, so that 2 amps flow.&nbsp; just like you'd expect from a <a href="https://cellsaviors.com/blog/diy-bench-power-supply">DIY adjustable bench power supply</a>. So, the batteries have a certain voltage, this is set to a certain maximum, and it will change the voltage to whatever it has to be in order for that amount of current to flow.If I change it to 1 amp, let's see what happens. Right now, they have to bring the output voltage to 25.9 for 2 amps to flow—25.9 volts. I did it again—wrong button. So, let's set it to 1 amp. Now it sets the output to 25.6 because that's what it takes for 1 amp to flow. So as you can see, we're not really doing the amps thing; we're doing the voltage and resistance thing. The amps thing is just something that happens, and we're good at measuring that. The current is just the end result of what you do with the voltage and the resistance.That's the second or third way to use this: you can charge your battery, use it as a basic voltmeter, and use it to power a lower voltage device with a higher voltage input. That's three.<h2>Battery-to-Battery Charging</h2>Let's go to the next one. I'll unplug this AC-to-DC power supply. Yep, a little too tight—I’ve got to work on that. Mostly off camera, I have this massive EM3 EV e-bike battery. It's a 16S—sorry, it's a 14S—and I've got it charged to 50-something volts. I don't know, let's just plug it in here. There we go.This battery has a power switch. There we go. Okay, so what's our input voltage? 54.98 volts. My Amazon listing says this has a max input of 50 volts, but the capacitor in my experience disagrees. Also, there are different listings for this, so it's kind of hard to interpret. So if our input voltage is 54.98 from this battery and our output voltage is 27.16, that means that we can safely connect these two batteries together. I've got the other battery now, and we are transferring energy from the large battery to the small battery. Battery to battery charging is super useful in a lot of situations.<h2>Using the Regulator for Cell Group Charging</h2>Now, I've set it to 4.16 volts and the current to basically zero—it's as low as it goes. That makes it safe to use as a voltmeter as long as I don't reverse the polarity. Here we have this 10S 3P Jetson Bolt Pro OEM eBike battery. As you can see, it's made out of 10 cell groups in series, and I'm interested in just this group. As long as I connect the terminals over just that group, then it may as well be sitting there by itself—it doesn't matter that it's in series.I can see that the cell group is at 3.72 volts while the other cell groups are at 3.85 or so; this one's particularly low. So if I want to charge this individual cell group, all I have to do is first disconnect it, then set the current to whatever we think is safe. These are two-amp-hour cells, and there are three in parallel, so just do three amps—it'll probably be fine. And that is right here.The problem I have with the screen mainly is these words. The letters here represent words, and those words don't really mean anything compared to the actions of these buttons. There's a UI button here—well, they’re both user interface buttons. This might mean "switch" or something. They’re both switches. You know, I'm not sure what's going on here.Anyways, I have this set to 4.16 volts and three amps. Now we can connect this, and here we go. So another way you can use this is to rapidly charge a cell group. Now, remember, I'm charging this to 4.1-something volts; I don’t want to do that. So let's turn this off—which is just as good as unplugging it—and then change it to 3.85 because that's what the other cells are at, at least according to this device. And we just want them to be the same, right? I did it again—there we go, close enough. You get my point. We can turn the output back on, and we are charging that cell group.The only reason why it's not going to the current that I set is because it's already charged close enough to that to where the separation in the voltages just isn't enough to make that amount of current. That’s why the CC (constant current) light is off—because it's currently operating (no pun intended) in constant voltage mode.<h2>Final Thoughts and Pricing</h2>These are really great regulator boards that work on a wide range of inputs and offer a wide range of outputs in terms of voltage and current. You can run them from DC power supplies, they get their power from AC, or you can run them from batteries. You can use them to power devices that have nothing to do with batteries, or you can use them to charge batteries. There are so many things you can do with this regulator, and it's super cheap. The price always fluctuates. The last time I checked, it was just under $30; I bought one of these before for $22. Like I said, the price changes all the time, but they're totally worth like $50.This is a really good regulator. It does everything that it says it's supposed to do—and a whole lot more than that, really.

Why do lithium batteries sometimes burst into flames while charging? 

What Is Thermal Runaway?

Sometimes, when you charge <a href="https://cellsaviors.com/blog/lithium-cell-battery-safety">lithium ion batteries too fast</a>, they catch on fire. This could be the result of thermal runaway while charging. I say "could" because not all lithium ion battery fires are related to thermal runaway. If you have a fire related to thermal runaway, you're in for a really bad day.&nbsp;<h2>What Is Thermal Runaway?</h2>Thermal runaway, essentially, is when something gets so hot that it cannot stop getting other parts of itself hotter and hotter. Because things that experience thermal runaway are generally things that don't react well to heat, once you heat them up, they start to have reactions that produce more heat.Once the situation gets so bad, your internal thermal runaway will quickly transition to an external thermal runaway, in which now, instead of the unwanted heat propagating throughout a single thing, such as a battery cell, it will now be propagating through many battery cells as they all experience the cascading effects of thermal runaway.<h2>Thermal Runaway Explained</h2>We are gonna go on a bit of a tangent here, but bare with me. To effectively demonstrate thermal runaway, consider a piece of paper. It takes a certain amount of energy to cause that piece of paper to catch on fire. The paper is the fuel in the fire triangle, the air in the room is the oxygen, and the third part of the fire triangle is energy. As we know, in order to have fire, all three parts of the fire triangle must be present.If I rub that piece of paper with my hand, it's just not enough energy to make it catch on fire. I can probably get the paper warm so that if you feel it after I rubbed it really hard, you could feel the warmth, you can feel the energy that I put into the paper, but it just wasn't enough energy to cause the paper to catch on fire. However, there is a very common device that can be used to easily put more than enough energy in that piece of paper for it to catch on fire—it's called a lighter. If I take a lighter and I start a very, very small flame at the very, very corner of that piece of paper, that tiny little flame does not contain enough energy to burn up the entire piece of paper, but it does contain enough energy to burn up the tiny corner of the paper that it's on.One of two things will happen if I leave this unattended. It will either fizzle out and go to smoke, and the paper will stop burning, or it will experience thermal runaway. Thermal runaway would happen if the angle of the paper was just right so that the flame was touching more of the paper that was not burned yet, or if the wind or air currents in the room moved just right to spread the flame out in just the right way that the process became large enough to become self-sustaining. This is the basic principle of starting a fire.It's relatively easy to get something to smoke. It's even relatively easy to get a small flame, but it takes some level of skill or effort to actually build a proper fire and have it burn properly. When you build a successful fire that becomes self-sustaining, what you've done is you have successfully achieved thermal runaway.It's when the stuff is so hot that it just can't help but continue to get stuff next to it hot, and the amount of heat that's added to the additional material is enough for it to burn and therefore release more energy and heat up other things next to it. Once thermal runaway has been achieved, unless you suck all the oxygen out of the air, it will simply burn until there's no fuel left.<h2>How Does Thermal Runaway Happen When Charging Lithium Ion Batteries?</h2>Lithium ion batteries have specific charge and discharge limits. This is because batteries store their energy in the form of reversible chemical reactions. Those reactions are not instant, and they take some time to propagate through the entire cell. This time, and other factors, cause this process to have what is equivalent to placing a resistor in series.As you pass current through any resistor, the voltage is going to drop. That voltage drop multiplied by the current will give you the amount of power, in watts, that is dissipated within the cell.&nbsp;<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:372,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXePbUKA9-G5tB1V4mL7Qe99EbTt2OALlY41TWJRMcVOkdcfkV03FzRvu2E1qsBYZDPp4UW6wkGJHkjGKqlfRw3sFe0MFg4LRmF_kqjxfzpfkiLkxtlPLwfnXlJI4_A4wUndsnfOTw?key=Tfa1Yg0FDhtXjhNSTLpoNM0u&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXePbUKA9-G5tB1V4mL7Qe99EbTt2OALlY41TWJRMcVOkdcfkV03FzRvu2E1qsBYZDPp4UW6wkGJHkjGKqlfRw3sFe0MFg4LRmF_kqjxfzpfkiLkxtlPLwfnXlJI4_A4wUndsnfOTw?key=Tfa1Yg0FDhtXjhNSTLpoNM0u" width="624" height="372"><figcaption class="attachment__caption"></figcaption></figure> Why Do Lithium Ion Cells Get Warm While Charging?It's a little known fact that the lithium ion charging process is actually endothermic, so that means it absorbs heat, but this effect is only at a few milliwatts. The reason cells don’t feel cool to the touch and still get warm while charging is because of the heat generated by ohmic resistance, which is actually a bit higher in the charging direction.&nbsp;Also, as a lithium ion battery reaches its full charge voltage, its resistance creeps up a little further, adding more heat to the system. &nbsp;So we know that battery cells get warm when any current is passed through them, and we know they get warmer as they're charging, despite the charging process itself actually absorbing a little heat.And we know what thermal runaway itself is, so we can put it all together into one package and clearly see that if you charge a battery pack too quickly, it can experience thermal runaway and cause a very bad chain reaction.As a battery gets older and older, its resistance increases, but the charger you’re using doesn’t know the age or health of the battery, so it’s going to charge it with the same current it always does.So what that means is, for any lithium-ion battery, every time you charge it, it gets a little hotter during the charging process because its resistance increases over time. This just happens very slowly.If the <a href="https://cellsaviors.com/blog/bms-lithium-batteries">BMS doesn’t have a temperature sensor</a>, and if the battery was already built in a way that it was going to get hot under charge normally—because it doesn’t have enough cells for the amount of current being put into the battery—towards the end of that life span, that battery just may tip over into the danger point as it becomes hotter and hotter under charging, and it could experience thermal runaway.A lot of the time, the BMS will be able to support a certain amount of charge current that’s above the amount the cells can support, but the manufacturer supplies the charger, and it’s a small charger—like a 2 or 3 amp charger—so they don’t think anything of it.But the customer wants a faster charger, buys an appropriate-voltage lithium-ion charger and an adapter, or finds one with the right connector, and everything works fine.The BMS has a 10 amp limit; the cells can only handle 5 amps of charge current, and he’s got a 6 amp charger.In this situation, everything will work fine most of the time, but after a really hard ride, where the cells are already hot from discharge, and you throw it on a charger that overloads it, you could have a serious problem on your hands.<h2>Final Thoughts</h2>In the end, thermal runaway while charging a lithium-ion pack really comes down to a vicious feedback loop: you shove current in faster than the cells can comfortably absorb, they heat up from resistive losses (and even absorb a little heat as they charge), and as their internal resistance creeps up with age or state of charge, they heat up even more.If that extra heat can’t be whisked away––either because the cell layout doesn't have enough cells in parallel, the BMS has no temperature cut-off, or you’ve simply over-amped the charger ––you’ve lit the fuse for a cascading fire. Once one cell tips over into thermal runaway, it will ignite its neighbors until the whole pack goes up in smoke (or worse). So, bottom line: respect the cell’s charge limits, match your charger and BMS to the battery’s capabilities, and keep an eye on temperature. Push it too hard, and you could easily have a heat related catastrophe.&nbsp;

Thermal Runaway While Charging

The age old debate of voltage vs current in article form.

Voltage Or Current - Which Kills You

So, is it the voltage that kills you or is it the current? The age-old question—endlessly debated for well over a century.Voltage can be thought of as the pressure of the electricity because voltage is literally the energy per unit charge of the electricity. Resistance is the amount in which a given material will resist the flow of that electricity, and current is the rate at which that electricity ends up flowing considering the amount of energy it had in the first place and how difficult it is for that energy to move through a given material. In this article, we will explain in depth what voltage, current, and resistance are. We will also explain how those things combine to form power. This might be somewhat of a controversial article, but let's get started.<h2>What is Voltage?</h2>Voltage is, quite literally, the measure of the potential energy per charge between two points. Put simply, voltage is the ability for a given material to create electricity. In order for electricity to happen, you have to have two things that have a difference in charge come into contact. Once that happens, that creates a voltage at that moment—that is when voltage is created.A <a href="https://cellsaviors.com/blog/diy-bench-power-supply">power supply </a>creates a voltage like this. It uses various devices, components, and techniques to increase the charge on one side of the circuit while keeping the charge on the other side at a particular reference point. This difference in charge creates the voltage. Voltage only exists when there is a difference; if there is no difference in charge, there is no voltage.Humans are really smart, so we can make all kinds of devices and combine all kinds of materials to control the charge of a particular thing. We can do that so well that we can control the charge between two particular things so precisely that we can produce exactly 12 volts of difference. Whenever you refer to voltage, you're really referring to how many volts of difference there are—because voltage is, by definition, a difference. If there's no difference, there is no voltage.A battery creates a voltage like this. We create two different materials that, by their very nature, have two different levels of charge. We keep those materials separated so that they don't come into contact inside the battery. Then, we connect conductors to the outside of the battery so we have a positive and negative terminal.&nbsp;<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/png&quot;,&quot;filename&quot;:&quot;微信图片_20250418093406.png&quot;,&quot;filesize&quot;:1307805,&quot;height&quot;:1024,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/f5D9D4s6eYeZ7VySHrsA4oQjozWYiJxQKrai3pcW.png&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/f5D9D4s6eYeZ7VySHrsA4oQjozWYiJxQKrai3pcW.png&quot;,&quot;width&quot;:1024}" data-trix-content-type="image/png" data-trix-attributes="{&quot;caption&quot;:&quot;Battery voltage diagram&quot;,&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--png"><a href="https://admin.cellsaviors.com/storage/f5D9D4s6eYeZ7VySHrsA4oQjozWYiJxQKrai3pcW.png"><img src="https://admin.cellsaviors.com/storage/f5D9D4s6eYeZ7VySHrsA4oQjozWYiJxQKrai3pcW.png" width="1024" height="1024"><figcaption class="attachment__caption attachment__caption--edited">Battery voltage diagram</figcaption></a></figure><h2>What is Resistance?</h2>This one's pretty easy to conceptualize, because resistance literally is just that—it is the resistance to the voltage, or how much it's going to lower the voltage. Resistance is the property of the material that defines how much the input voltage will be different from the output voltage. And one might interject and say, well, actually, a resistor regulates the flow of current in a circuit. Right, but how does it do that? If you are interested in resistance, then check out our article on resistance and <a href="https://cellsaviors.com/blog/the-effects-of-reistance-on-a-battery">how it affects a battery's performance</a><h2>How Does A Resistor Limit Current?&nbsp;</h2>A resistor affects the current flow by creating a voltage drop across itself, so it is lowering the voltage along the path of the circuit. Here is how it happens:&nbsp;<ol><li>In a circuit, with a voltage source (like a battery), the total voltage from the source remains constant (say 12V).</li><li>When current flows through a resistor, it creates a voltage drop across that resistor according to Ohm's Law (V = IR).</li><li>This voltage drop means that the electric potential decreases as current moves through the resistor - so yes, the resistor is effectively "lowering the voltage" at points after it in the circuit.</li><li>The resistor limits current flow because the voltage drop it creates must obey Ohm's Law. Since the voltage source is fixed, the current must adjust according to I = V/R.</li></ol>For example, in a simple circuit with a 12V battery and a 4Ω resistor, the current will be 3A because I = V/R = 12V/4Ω = 3A. The resistor creates a 12V drop across itself, and this voltage drop is what limits the current to 3A.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/png&quot;,&quot;filename&quot;:&quot;微信图片_20250415152634.png&quot;,&quot;filesize&quot;:1558076,&quot;height&quot;:1024,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/wVnEKpEx7uDYjMDQ3d2rfP3yRk6XeLzbbNnriyqP.png&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/wVnEKpEx7uDYjMDQ3d2rfP3yRk6XeLzbbNnriyqP.png&quot;,&quot;width&quot;:1024}" data-trix-content-type="image/png" data-trix-attributes="{&quot;caption&quot;:&quot;Basic Circuit with Resistor&quot;,&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--png"><a href="https://admin.cellsaviors.com/storage/wVnEKpEx7uDYjMDQ3d2rfP3yRk6XeLzbbNnriyqP.png"><img src="https://admin.cellsaviors.com/storage/wVnEKpEx7uDYjMDQ3d2rfP3yRk6XeLzbbNnriyqP.png" width="1024" height="1024"><figcaption class="attachment__caption attachment__caption--edited">Basic Circuit with Resistor</figcaption></a></figure>So, resistors do work by creating a voltage drop, which directly limits the current flow. In practical terms, we can absolutely think of resistors as lowering the voltage along the path of current flow.The difference between the input voltage and the output voltage of a resistor is directly related to the rate at which the voltage is moving through the resistor. So if the voltage is moving through the resistor twice as fast, then it will produce twice as much voltage drop.Imagine a fluid that an object is entering at a given speed, and it's attempting to pass through this fluid. The speed when exiting this fluid will be lower than the speed at the time of entering the fluid. If resistance is the fluid, then we can think of resistance as a type of material that, the faster you try to move through it, the more your exit speed will be reduced. Traditionally, we might think of a bullet going through a block of ballistics gel—in that situation, the more speed you have going in, the more speed you're going to have going out, even though the speed will always be lower. But in this situation, resistance has the properties such that as you move through it faster, its ability to slow you down increases instead of decreases.<h2>Electronics Work At The Quantum Level</h2>I know that sounds really strange, but that's okay because we are literally dealing with the quantum world here. The things that we are describing with volts, current, amps, ohms, resistance—all of that is just our way to classically describe a quantum thing. Quantum things don't have to obey classical physics.For example, if we have a certain amount of balls in a given amount of space, we can absolutely predict with a very high degree of accuracy exactly where those balls are because we can measure them. But electrons can't be measured like that. We can only predict with a certain degree of accuracy the probability of their position at any given point. We can't even say with certainty that an electron is not two feet from its nucleus. All we can say with certainty is that it's 0.0001% likely to be there, so basically unlikely to be there.And as you get closer and closer to where they actually are, the probability that they are there increases to almost, but never, 100%. This doesn't make classical sense, but it makes quantum sense. So we don't really have to understand why these things are happening; we just have to understand that it's true that they are happening, and we have to be able to relate how it will happen and what those effects will be with mathematical certainty. We don't have to be right about it, it just has to work.<h2>What is Current?</h2>Current is the rate that the electricity moves through the circuit. It is the rate in which electric charge flows. So, consider a two-ohm load with a 12-volt circuit. A circuit by definition connects back around to itself—that's why it's called a circuit. If we increase the charge on one side of the circuit to whatever level is required to produce 12 volts of difference when connected to the other side of the circuit, and put a two-ohm load in series with that, electric charge will flow. And the rate in which it flows, we measure in amps.Ultimately, power supplies generate power that can be used because they maintain the difference between the high side and the low side of their outputs, and they are rated to maintain that difference up to a certain amount of speed. So, we can follow the entire path to see exactly when current is created. You either have a power supply that has active components or a battery that has material properties that produce two components that have different charges. When those two components come into contact, a voltage is created up to a particular maximum voltage. The actual voltage that's created depends on not just the resistance of the contact, but the resistance of the inside of the power supply or battery and every other part of the circuit—the wires, the connectors, the solder joints, the welds, the crimps; it all adds up.That means we can't just consider the resistance of the load, which is two ohms. We also have to consider the sum total resistance of everything else. So, let's just say, for simplicity's sake, that the entire power supply and circuit and everything is 140 milliohms. We add that to our two-ohm figure. Current is the measure of the end result speed of the electricity moving through a given material. It's easy to find the speed because all you have to do is divide the voltage by the resistance.If we take 12 volts and divide that by 2.14, we get 5.61. We know the speed of the electricity moving at any point throughout the circuit is 5.61 amps. The amount of power that happens as a result of that can be calculated by multiplying that speed by the voltage drop over a given section of the circuit. That comes out to 62.94 watts—that's the power for the entire circuit. But because only around 0.79 volts of that total voltage drop happens outside of the load, only a very small portion of the power is dissipated there. The overwhelming majority of the power goes to where there is an 11.22-volt drop across that two-ohm resistor, the load.So, current itself, while it's very important, is just the end result of how electricity moves through resistance. With a given voltage and a given resistance, the energy will be able to move through that circuit at a given speed. If it's 12 volts and 6 ohms, the speed will be 2 amps. If it's 5 volts and 2.5 ohms, the speed will also be 2 amps. If it's 100 volts and 1,000 ohms, the speed will be 0.1 amps. Multiply the speed by the voltage, and you get the power. That's how the current is the same through the wires, connectors, and everything else, but most of the power isn't going there because the voltage drop in that area is lower, because the resistance is lower.<h2>What Kills You? The Volts or the Amps?</h2>So, what kills you? The volts or the amps? The answer is either or, or maybe both. I mean, you could also say it's the resistance that kills you; you could also say it's the charge that kills you. We could trace it all the way back through the conservation of energy, matter, momentum, and all of that stuff, and we can say the big bang is what really killed you. But the order of operations is important. The voltage definitely happens first, and the amps are just the speed that that voltage is happening.So, what kills you? The bullet or the speed at which the bullet made contact with you? Technically, both of those things are true. If a much lighter thing hit you at the same speed, you wouldn't die. And if a much heavier thing hit you at a slower speed, you would die.So, when it comes to what kills you—the volts or the current—the current is the one actually doing the killing. But if you don't have enough voltage, there will not be enough current to harm you because of the resistance of the human body. Another thing to consider is the fact that, ultimately, the voltage is the star of the show. It's the voltage that may or may not be limited enough by the resistance to kill you or not, and the current is just the end result—the speed of the electricity moving through that resistance. And you have to multiply that by the voltage anyway to get enough watts to kill you. So, I feel like it's the voltage that kills you.

Is It The Voltage That Kills You Or The Current

A full breakdown of the benefits of a 72V battery

The Benefits Of A 72V Battery

Ah yes, the 72 volt battery, the ultimate goal for any e-bike enthusiast. And while the 72 volt battery is desired by so many, they can often be misunderstood. In this article, we'll talk about all of the benefits related to 72 volt batteries, whether a 72 volt battery is worth it, and what really are the performance and efficiency benefits when considering a 72 volt battery over, say, a 48 volt battery or a 52 volt battery. We'll answer some other key questions, such as: can you combine two 36 volt batteries to make one 72 volt battery? And much, much more. So, let's get started.<h2>What Is A 72V Battery?</h2>First of all, what is a 72 volt battery? Well, that quickly brings us to a problem. Batteries are given a voltage just to make it easy to explain them to people. In reality, a battery is never 72 volts. A 12 volt battery is never 12 volts. It's not 12 volts most of the time; it's not 12 volts a good chunk of the time—it’s basically never 12 volts. How batteries work is they have some sort of voltage, and as you use them, the voltage falls. So, a 72 volt battery, if it had a full charge voltage of 72 volts, would never be a 72 volt battery because the voltage would immediately start falling.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/png&quot;,&quot;filename&quot;:&quot;yp8OSsd4raWXJYqzh7Xd6EW26GGQjaTT1ZIhwuzo.png&quot;,&quot;filesize&quot;:1373358,&quot;height&quot;:644,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/OkQMPqjINo6hKvbFpF8StqccAWkasjY1oGBQ8Tlg.png&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/OkQMPqjINo6hKvbFpF8StqccAWkasjY1oGBQ8Tlg.png&quot;,&quot;width&quot;:855}" data-trix-content-type="image/png" data-trix-attributes="{&quot;caption&quot;:&quot;image.png 1.31 MB&quot;,&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--png"><a href="https://admin.cellsaviors.com/storage/OkQMPqjINo6hKvbFpF8StqccAWkasjY1oGBQ8Tlg.png"><img src="https://admin.cellsaviors.com/storage/OkQMPqjINo6hKvbFpF8StqccAWkasjY1oGBQ8Tlg.png" width="855" height="644"><figcaption class="attachment__caption attachment__caption--edited">image.png 1.31 MB</figcaption></a></figure><h2>Battery Voltage And Chemistry</h2>'We get to these battery voltage numbers by using something called the cell's nominal voltage. For NMC chemistry—which is the most popular type of lithium ion battery—the nominal voltage is 3.7 volts per cell. So, to get to 72 volts, you have to put 20 of those cell groups in series. The funny thing is that doesn't even bring you to 72 volts; that brings you to 74 volts. Then, we have to go back to the data sheet and realize that sometimes they go by 3.6 volts nominal voltage, other times they go by 3.7 volts. It doesn't really have much to do with the chemistry specifically—it's more about marketing. Because regardless of a 3.6 volt nominal or a 3.7 volt nominal cell, they never go to those voltages. That's just an average of the general area it's going to be most of the time. It's true that the cell voltage starts to fall quickly when it's at 4.2, then slows down as it gets closer to 3.7, and then speeds up again as it's leaving that area. But it never goes to 3.7 or 3.6. If it ever is 3.7, it's for a fleeting, tiny moment. The point I'm trying to make is that there's really no such thing as a 72 volt battery; but we've got ourselves in this situation where we call a certain type of battery a 72 volt battery. That's generally going to be a battery that has a nominal voltage of 72 volts. You get to that by putting a certain amount of cell groups in series. If it's NMC chemistry, as I just said, it takes 20 cell groups in series. But LFP, which is another popular lithium ion chemistry, has a lower voltage. So, you take the 72 volts and divide that by 3.2, and you get 22.5. And since we can't do half a cell group, we have to do 23 cell groups in series. That means if you have a 72 volt battery that's made with NMC chemistry, it will have a voltage range of about 60 volts to 84 volts. But if you've got a 72 volt battery with LFP chemistry, it's got a voltage range of about 62 to 85.1 volts. It's pretty confusing, right? The good news is that generally any 72 volt device will work in the range of a 72 volt battery, and there's always some amount of wiggle room there. So, to get back to the question of what is a 72 volt battery, with today's common battery technologies, that would be a lithium ion NMC battery that has 20 cell groups in series, a lithium ion LFP battery that has 23 cell groups in series, or a lead acid battery with a whopping 36 cell groups in series because of the stunningly low nominal voltage of 2.0 volts.<h2>Combining Two 36 Volt Batteries to Make a 72 Volt Battery</h2>So, can you combine two 36 volt batteries to make a 72 volt battery? Yes, you can, but you can only use it until one of them dies. I'll explain.If you're combining batteries—and using batteries and all of that—I'm just going to go ahead and assume that you're using a BMS. If you're not using a BMS, then we have a whole additional problem, and you should probably check out our <a href="https://cellsaviors.com/blog/bms-lithium-batteries">article on BMS</a>.<h2>Understanding the BMS (Battery Management System)</h2>Combining two 36 volt batteries into one 72 volt battery requires that both of those batteries have a BMS. You'll run into this issue:First of all, I’ve got to do a quick primer on a BMS. A BMS keeps track of all the important stuff going on in your batteries, like the individual cell voltages, the current, and stuff like that. If anything goes out of spec, it turns the battery off. It's able to do that because all of the current flows through a MOSFET, and it can control the gate of that MOSFET and use it as a switch to control the flow of current.The MOSFETs used as switches inside a BMS are rated for a particular voltage. They can't handle just any voltage. The company that manufactures the BMS is going to select the most economically viable MOSFETs for the job. So, you can bet that the MOSFETs inside a 36 volt BMS aren't going to be rated for much more than the max charge voltage of a 36 volt battery.&nbsp;Seeing as we know the max charge voltage of a 36 volt battery is 42 volts, and we know the MOSFETs on the inside of the BMS will be able to handle at least that—and probably a little bit of buffer unless they're a really, really shady electronics manufacturer—this means you can probably get away with maybe 50 or 52 volts, but it's hard to find MOSFETs rated for that voltage. So, then you pick the next one up, which is usually 60 volts.If you notice something about 60 volts, it's less than 72 volts. And 72 volts isn't always the voltage of a 72 volt battery; remember, it could be as high as 84 volts. Some people might interject and say, "Well, I've hooked two 36 volt batteries with BMS up together, and they work just fine." Yes, that's true. Even though those transistors are not rated for the combined voltage, they don't see the combined voltage—because that's how transistors work. They have an extremely high resistance (basically an insulator when they're off), but they have an extremely low resistance (basically a conductor when they're on).That means when they're on—when both batteries are charged and working—the path from gate to source is going to have almost no voltage drop. The only voltage drop you're going to see is the drop over the transistor itself, which is very power efficient. So, that voltage drop is going to be very low, and it's going to work just fine. But the moment one of those batteries dies, it will send the signal to the gate of its MOSFETs and it will turn off the MOSFETs, at which point the resistance will be very high.Then, those MOSFETs will see the voltage of both batteries combined. You may even get lucky in this situation and not burn up your BMS. A lot of the time, it'll fry the BMS immediately. Other times, smoke will start pouring out of the batteries. There's a lot that can happen. Most of the time, you just wonder why you can't charge your battery again—it’s because one of them died and it fried itself from that effect.So, the answer to the question of "can you put two 36 volt batteries together in series to make a 72 volt battery?" is: yes, as long as neither one of them dies while you're using it. So, if you don't have far to go, or if you just want to do a drag race or some experiment, then okay. If you have two large 36 volt batteries—or even two batteries that have wildly different capacities—as long as the smallest of the two has more than enough energy for you to do what you need to do, then yes, you can put two 36 volt batteries in series to make a 72 volt battery.<h2>Benefits of a 72 Volt Battery: Performance and Efficiency</h2>So, what are the benefits of a 72 volt battery? What does the higher voltage give you in terms of power? And what efficiency improvements come along with that?Well, in terms of power, it works like this: If you have a motor that operates at 36 volts and it consumes 10 amps, if you double the voltage, you would have to put it under twice as much load for it to draw that many amps. So, if you put it under the same amount of load as before (so you go the same speed as before, you accelerate as hard as before), your motor will only be using five amps at the higher voltage.This is because the resistance of the motor didn't change, but the voltage doubled. That means the amount of watts, or power, that the motor has access to is doubled. So, if you double your voltage and don't double your load, you're consuming the same amount of power as before, but at half the current. This results in half the efficiency losses, assuming everything else is equal.But you have an entirely additional range of performance on top of that, which you can access because you've doubled the voltage. So, however fast your bike went before on 100% throttle, it will go that fast at 50% throttle. Then, everything from 50% throttle to 100% throttle will be additional performance. This is, of course, assuming that the controller in question supports that voltage range.<h1>Efficiency Analysis</h1>Let's talk about efficiency. Here, we have a typical 36 volt lithium ion battery with a standard nickel construction using mid-grade cells. This particular battery has a resistance of 95 milliohms. As you can see from the chart, it can output almost 40 amps before it dips below 90% efficiency. That gray dotted line is the expected power—that is, if you just take volts and multiply by amps, but that's only the power you would get in a perfect world.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:517,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXdZP9IAu3znpkEajPATHkNKeQd6gIA9n_VJru1zCOy74qVci01mJeK9hMzq3EW46clqNH5pZRm479BE6-PrAYg3vnncBirrUT13PCM0BOFANBV3xXbH36pcCKHM3Bc5GhZZnIGm?key=4dwnAOlJ10o11Sm5BbGD6NOO&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXdZP9IAu3znpkEajPATHkNKeQd6gIA9n_VJru1zCOy74qVci01mJeK9hMzq3EW46clqNH5pZRm479BE6-PrAYg3vnncBirrUT13PCM0BOFANBV3xXbH36pcCKHM3Bc5GhZZnIGm?key=4dwnAOlJ10o11Sm5BbGD6NOO" width="624" height="517"><figcaption class="attachment__caption"></figcaption></figure>We live in the real world, where every part of the system has resistance, and it all adds up to a sum total resistance. Because its resistance is 95 milliohms, this battery can stay within 10% of the expected power up until that line turns red. After the line turns red, that's when it deviates more than 10% from the expected power, meaning it's less than 90% efficient.So, as long as you run this battery at about 40 amps or less, you won't have any problem with it. At that current level, it can be considered a decent battery because it will probably be reliable at those currents, and it won't overheat or cause any fires. But if you look, you're still getting a 4-volt drop at 40 amps. That means if your battery is at 36 volts, you're only able to put 32 volts of power down. But that's okay—it's still a decent battery.Now, what happens if we build a battery exactly like that, but we change absolutely nothing: we keep the same cells, the same layout, and everything—the same series conductors—and we just extend that further 10 more groups to make a 72 volt battery. What would happen? Well, isn't that interesting? It seems like we haven't improved the efficiency at all. Look: it still deviates 10% from expected power right before 40 amps, and you still drop to about 90% efficiency at 40 amps.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:517,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXe3FHGr-7EiSwDCdUgC0ywGmywvt2J4A1OzaDYIMQfXUJq36OjLE_WlSo6CGXbtbEW2xl6hRJ3UOkvskAbAy5QysCy5XCY7hQjUYN8KyHULguQ1JPJMzAJMak5N29o0oQbUpSHf?key=4dwnAOlJ10o11Sm5BbGD6NOO&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXe3FHGr-7EiSwDCdUgC0ywGmywvt2J4A1OzaDYIMQfXUJq36OjLE_WlSo6CGXbtbEW2xl6hRJ3UOkvskAbAy5QysCy5XCY7hQjUYN8KyHULguQ1JPJMzAJMak5N29o0oQbUpSHf?key=4dwnAOlJ10o11Sm5BbGD6NOO" width="624" height="517"><figcaption class="attachment__caption"></figcaption></figure>But because the voltage is doubled for each amp, we have twice as many watts. If we put both of these batteries on the same chart and follow their paths out to that 10% cutoff point and compare them side by side, it becomes clear that a 72 volt battery is about 5% more efficient than a 36 volt battery at the same load.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:397,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXcgxmlsDom6eS7uMNMpre4-2BpDjlRBtah7HEBpOr0XHzhFEpUznvk3WBrhwh-41nccDq4_cwwD-ZTD_-y1GsCI1Qq8mMjDxninE9zajdNLMOUDTtC68fzeMJLN_jFbVJoDP36elA?key=4dwnAOlJ10o11Sm5BbGD6NOO&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXcgxmlsDom6eS7uMNMpre4-2BpDjlRBtah7HEBpOr0XHzhFEpUznvk3WBrhwh-41nccDq4_cwwD-ZTD_-y1GsCI1Qq8mMjDxninE9zajdNLMOUDTtC68fzeMJLN_jFbVJoDP36elA?key=4dwnAOlJ10o11Sm5BbGD6NOO" width="624" height="397"><figcaption class="attachment__caption"></figcaption></figure>It takes a certain amount of watts to move your bike a mile. It's different for every bike, but it takes a certain amount of watts to move your bike a mile. That means if you get 30 watts per mile and you have a 60 watt charger, then you can charge it 2 miles per hour. You're getting 2 miles of ride time per hour of charge time.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:404,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXcGy9GqUsf1o6XMHR_gc-g9PBvuXB98bf89xipM5NIlDY5TsSF6Khq5uBNXwMRkX3lz_MSq4dX1bQyNsQad5wcjmkDF7BQjcFKd6YGLVXLhYKigR1Rk2iaJSPfeHSyqH6AfIKh-?key=4dwnAOlJ10o11Sm5BbGD6NOO&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXcGy9GqUsf1o6XMHR_gc-g9PBvuXB98bf89xipM5NIlDY5TsSF6Khq5uBNXwMRkX3lz_MSq4dX1bQyNsQad5wcjmkDF7BQjcFKd6YGLVXLhYKigR1Rk2iaJSPfeHSyqH6AfIKh-?key=4dwnAOlJ10o11Sm5BbGD6NOO" width="624" height="404"><figcaption class="attachment__caption"></figcaption></figure>Charging Benefits Of A 72V BatteryBecause the voltage is double, if you compare two otherwise equal 5 amp chargers, you're getting 355.2 watts into your battery for those 5 amps, compared to the 36 volt battery where you're only getting 177.6 watts. Of course, you're consuming more power from your utility company in doing so—you're not getting some magical benefit. It just so happens that the voltage is double and the current is still 5 amps.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:425,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXfxOK_TnQYcMXQFwm3RsGo4o913A79DDjEDF2P8Tyx7xrPkBmEHLmSxGTNadAr30v6lejlIIfSGKbeyIAqxb38RNpju8vbmcTPdSMC04PY6ZnRCsFbJdzehxHw1pkwmCGOOhct0eg?key=4dwnAOlJ10o11Sm5BbGD6NOO&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXfxOK_TnQYcMXQFwm3RsGo4o913A79DDjEDF2P8Tyx7xrPkBmEHLmSxGTNadAr30v6lejlIIfSGKbeyIAqxb38RNpju8vbmcTPdSMC04PY6ZnRCsFbJdzehxHw1pkwmCGOOhct0eg?key=4dwnAOlJ10o11Sm5BbGD6NOO" width="624" height="425"><figcaption class="attachment__caption"></figcaption></figure> You're getting more charge time for the amount of current that you're putting your battery under in terms of stressing it from charging it. Again, when you charge a 72 volt battery, you're doing half of the charging damage you would normally do per mile compared to a 36 volt battery.So, what have we learned? A 72 volt battery is defined by its nominal voltage rather than an absolute, fixed voltage. Whether you're dealing with an NMC battery made of 20 cell groups in series or an LFP battery made of 23 groups, the result is a system that offers a broader voltage range, enhanced performance, and improved efficiency. A higher voltage system not only doubles the available power per amp but also reduces current draw at the same power level as before, which in turn minimizes efficiency losses and charging stress. However, when combining batteries—like linking two 36 volt batteries in series—you have to be careful because of the BMS MOSFETs voltage rating. Ultimately, 72 volt batteries provide more power and are more efficient than an otherwise equal lower voltage setup.&nbsp;

72 Volt Battery

Lets investigate the effects of resistance in series conductors on lithium ion battery packs!

The Effects of Resistance And On A Battery

Looking for names and models of the highest capacity 21700 batteries on the market, look no further we have you covered!

What is the Highest Capacity 21700 Cell

The highest capacity 21700 is the XTAR 21700 6000mAh. The closest runner-ups are Vapcell's F60 (6000mAh) and BAK's 5.5Ah (5500mAh) cell. The XTAR 6000mAh cell is not particularly hard to come by, but it is relatively expensive at over $15 per cell. If you're looking for alternatives, the Vapcell's F60 and BAK 5.5Ah are good options, though they are slightly lower in capacity.These are the real figures for the highest capacity 21700, so if you see manufacturers claiming capacities above these figures, they may be misleading or inaccurate. So, make sure to verify capacity claims through trusted sources.These advancements in 21700 capacity reflect the rapid development of lithium ion battery cell technology. These new high capacity 21700 cells make lithium ion batteries even better for demanding applications like portable power tools, EVs, and high-drain devices.<h2>Where To Buy The Highest Capacity 21700?</h2>The XTAR 6000mAh cell can be purchased directly from XTAR. It's an expensive cell at over $15 per unit, but they are the highest capacity 21700 cells on the market. If the price is a bit too much, you may want to look into the Vapcell's F60 (6000mAh) and BAK's 5.5Ah (5500mAh) cells as they are solid options and don't have a built-in protection board. When comparing purchase options, XTAR may be the top choice if maximum capacity is a priority, while Vapcell F60 and BAK 5.5Ah are close runner-ups offering similar high-capacity performance at potentially better prices along with being more flexible in their application.<blockquote>[[ aff type=aff ~ link=https://shrsl.com/4qxoy ~ title=`Xtar 6000mAh ~ image=Xtar-6000MAH-21700-cell.jpg ~ description=`The highest capacity 21700 we have been able to find on the market!! 6100-6300mAh in our testing. ` ~ height=small ~ buttonText=`Check Price`&nbsp; ]]</blockquote><h3>XTAR 6000mAh 21700</h3>XTAR's 6000mAh battery is currently the highest capacity 21700 on the market. In testing at a 500mA discharge rate (equivalent to 0.083C, calculated as 500mA ÷ 6000mAh), this cell has consistently delivered between 6100mAh and 6300mAh, making it an excellent choice for long runtime applications. It's important to consider, however, that standard capacity tests are typically run at 0.2C, which would be 1200mA for a 6000mAh cell. So, that explains why we are getting test results much higher than the rated capacity.&nbsp;Xtar also offers the <a href="https://cellsaviors.com/blog/highest-capacity-18650">highest capacity 18650 cell</a> we have tested!It's not all sunshine and rainbows, though. Even though it is the highest capacity 21700, this cell has a built-in protection board that limits maximum discharge to 10 amps and makes the cells difficult to put in a series configuration. The protection board can also make it difficult to fit the cell into some testers and devices.&nbsp;<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/jpeg&quot;,&quot;filename&quot;:&quot;6000mah 21700 cell capacity test results.jpg&quot;,&quot;filesize&quot;:66659,&quot;height&quot;:338,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/aSN9VkNJVOVPW6ttRMoLphNHMeRHyH3gaZIF5XvB.jpg&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/aSN9VkNJVOVPW6ttRMoLphNHMeRHyH3gaZIF5XvB.jpg&quot;,&quot;width&quot;:309}" data-trix-content-type="image/jpeg" data-trix-attributes="{&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--jpg"><a href="https://admin.cellsaviors.com/storage/aSN9VkNJVOVPW6ttRMoLphNHMeRHyH3gaZIF5XvB.jpg"><img src="https://admin.cellsaviors.com/storage/aSN9VkNJVOVPW6ttRMoLphNHMeRHyH3gaZIF5XvB.jpg" width="309" height="338"><figcaption class="attachment__caption">6000mah 21700 cell capacity test results.jpg 65.1 KB</figcaption></a></figure><h3>Can Cells With A Built-In Protection Board Be Used In Series?</h3>It will work, but you have to be very careful, so it's not recommended. This is because in a <a href="https://cellsaviors.com/blog/series-lithium-batteries">series configuration</a>, if a cell fails or its protection board triggers a shutoff, the MOSFETs in that cell’s protection board enter a high-resistance (off) state. This introduces a large voltage difference between the drain and source of the MOSFETs in the shut-off cell due to the series arrangement.The entire voltage of the remaining active cells in the pack is now applied across the MOSFETs of the failed or disconnected cell. Since the MOSFETs are only rated for single-cell voltage, this sudden exposure to the full pack voltage can cause them to exceed their tolerance and fail. This vulnerability makes protected cells poorly suited for series configurations, as a single cell’s failure can lead to over-voltage damage across its protection circuit, compromising the whole pack.<h2>21700 Battery Capacities Over Time</h2>The development of 21700 batteries has paralleled the trend in 18650 cells, with a steady increase in capacity thanks to advances in battery chemistry and manufacturing. Initially, 21700 batteries were produced with capacities of around 3000mAh to 4000mAh. Over time, new designs and improved materials have led to significant capacity improvements, culminating in today’s 6000mAh cells. However, even with continued progress, we have yet to see a commercially viable 21700 cell exceed the 6000mAh mark.<h3>Determining 21700 Battery Capacity</h3><a href="https://cellsaviors.com/blog/amp-hours-capacity">Battery capacity is measured in milliampere-hours (mAh) or amp-hours (Ah)</a>, which indicates how long a battery can deliver a given amount of current before it dies. A 6000mAh battery, for instance, can theoretically supply 1000 milliamps (1 amp) for six hours, or 2000 milliamps (2 amps) for three hours, and so on.To <a href="https://cellsaviors.com/blog/battery-capacity-test">determine battery capacity</a>, a standardized testing process is used. The battery is subjected to a constant discharge current until it is depleted, allowing the total capacity to be measured. It’s worth noting that this test is typically performed at a modest discharge rate (between 300 and 1000mA). High discharge rates can cause a reduction in the effective capacity of the battery due to the heat generated during high current flow.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/jpeg&quot;,&quot;filename&quot;:&quot;21700 charger and capacity testers.jpg&quot;,&quot;filesize&quot;:74257,&quot;height&quot;:510,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/1fqgvg5xYrsuk9uLJT79r8Hw8j3owFC4K74w6PEX.jpg&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/1fqgvg5xYrsuk9uLJT79r8Hw8j3owFC4K74w6PEX.jpg&quot;,&quot;width&quot;:990}" data-trix-content-type="image/jpeg" data-trix-attributes="{&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--jpg"><a href="https://admin.cellsaviors.com/storage/1fqgvg5xYrsuk9uLJT79r8Hw8j3owFC4K74w6PEX.jpg"><img src="https://admin.cellsaviors.com/storage/1fqgvg5xYrsuk9uLJT79r8Hw8j3owFC4K74w6PEX.jpg" width="990" height="510"><figcaption class="attachment__caption">21700 charger and capacity testers.jpg 72.52 KB</figcaption></a></figure><h3>Beware of Inflated Capacity Claims</h3>As with 18650 batteries, you need to be wary of dubious claims when buying 21700 batteries. Some manufacturers and vendors will market products with incredibly high capacity numbers that are simply not achievable with current technology. If you see a 21700 battery claiming a capacity above 6000mAh, be skeptical, as this is beyond what’s currently feasible for this size of lithium-ion cell.Listings like this are typically scams, where manufacturers rely on misleading numbers to entice buyers. The cells may weigh more due to filler material, such as sand, to mimic the heft of a genuine high-capacity battery. Often, these batteries will also have significantly higher internal resistance and produce less current than advertised, making them unsuitable for high-drain applications.<h2>Beyond Capacity: Current Capabilities of 21700 Batteries</h2>When looking for the highest capacity 21700 battery, there are still other important factors to consider other than the amount of energy that can be stored in the cell. Discharge rate is also important, especially for applications that require substantial power draw. Generally, higher-capacity batteries, like the XTAR 6000mAh, tend to have lower maximum discharge rates. In contrast, cells such as the Samsung 50S and Molicel P42A can handle discharge rates of up to 25A and 45A respectively, though they come with lower overall capacities compared to the XTAR 6000mAh.If you need batteries for high-drain devices, you may want to prioritize those with higher current ratings that don't have a protection board, even if it means compromising on overall capacity. However, for devices where a steady, moderate power draw is all that’s required, the XTAR 6000mAh is the best 21700 for the longest runtime.<h2>The Future of 21700 Battery Technology</h2>It is expected that further advancements in battery chemistry will lead to even higher capacity 21700 batteries in the future. The next major development might come with graphene-enhanced lithium-ion cells or entirely new chemistries that can push beyond the current 6000mAh ceiling. Until those products become available, we’re just going to have to remember to be cautious of exaggerated claims and to purchase batteries from trusted manufacturers and vendors.<h2>What is the Maximum Capacity of a 21700 Battery?</h2>Currently, the maximum capacity for a commercially available 21700 battery is 6000mAh, as seen with XTAR’s 21700 model. This capacity is the highest verified figure on the market, with no reliable commercial options exceeding this specification as of the date of this writing.<h2>What is the Best 21700 Cell?</h2>The “best” 21700 battery capacity depends on the intended use. If capacity is the most important metric, then the XTAR’s 6000mAh is definitely the best 21700 cell. If, however, your application prioritizes both a mix of high capacity and high current, you may want to consider something like the Samsung 50S or Molicel P42A.<h2>What is the Battery Capacity of Tesla 21700?</h2>Tesla’s 21700 battery cells, commonly used in their Model 3, have a capacity of approximately 4800mAh to 5000mAh per cell. These cells balance capacity with performance, featuring an optimized chemistry that supports both energy density and the high discharge rates necessary for electric vehicle applications.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/jpeg&quot;,&quot;filename&quot;:&quot;bare tesla 21700 cell.jpg&quot;,&quot;filesize&quot;:33378,&quot;height&quot;:420,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/3JHHtrn8Ei9mIn1mfTegz8xNK6tAAp6gVZ5P1h8T.jpg&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/3JHHtrn8Ei9mIn1mfTegz8xNK6tAAp6gVZ5P1h8T.jpg&quot;,&quot;width&quot;:602}" data-trix-content-type="image/jpeg" data-trix-attributes="{&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--jpg"><a href="https://admin.cellsaviors.com/storage/3JHHtrn8Ei9mIn1mfTegz8xNK6tAAp6gVZ5P1h8T.jpg"><img src="https://admin.cellsaviors.com/storage/3JHHtrn8Ei9mIn1mfTegz8xNK6tAAp6gVZ5P1h8T.jpg" width="602" height="420"><figcaption class="attachment__caption">bare tesla 21700 cell.jpg 32.6 KB</figcaption></a></figure><h2>What is the Theoretical Highest Capacity 21700 Battery?</h2>The theoretical highest capacity for lithium-ion batteries is limited by the chemistry and materials used. For the 21700 format, the maximum achievable capacity with current technology is around 6000mAh. However, research into alternative chemistries, such as lithium-metal and graphene-based cells, suggests that future batteries may push well beyond this limit, potentially achieving even higher energy densities if these new technologies prove viable.As battery manufacturers push the boundaries of 21700 battery technology, several new developments indicate promising strides in both capacity and discharge rates. Battery research institutes in Asia and Europe are testing new 21700 prototypes that utilize lithium-silicon anodes, achieving an energy density 10-15% higher than conventional lithium-ion counterparts. These prototypes reportedly reach capacities around 6500mAh in lab settings; however, none have yet reached commercial viability.<h3>Upcoming Graphene-Enhanced Models</h3>Several manufacturers have also announced plans to integrate graphene-enhanced lithium-ion technology into the 21700 format within the next few years. Graphene's high conductivity may enable these batteries to support faster charging rates and improve cycle life. Though these graphene-enhanced cells are not yet available to consumers, initial testing indicates capacities that could reach up to 7000mAh, with discharge rates in the several 10s of amps, putting them on par with the Samsung 50S and Molicel P42A.<h2>How Much Difference Does a 6000mAh Cell Really Make?</h2>Here’s how higher-capacity 21700 cells impact battery pack performance in two examples—a 3S10P and a 13S4P configuration—demonstrating the advantages of choosing 6000mAh cells over 5000mAh cells for increased capacity and energy storage.<h3>Example 1: 3S10P Configuration</h3>In a 3S10P setup:<ul><li>Using 6000mAh Cells (XTAR 6000mAh):<ul><li>Each parallel group of 10 cells has a combined capacity of 60,000mAh.</li><li>Total capacity: 60,000mAh at 10.8V (3.6V nominal per cell × 3 series cells).</li><li>Total energy: 648Wh (60,000mAh × 10.8V).</li></ul></li><li>Using 5000mAh Cells (e.g., Samsung 50G):<ul><li>Each parallel group of 10 cells yields 50,000mAh.</li><li>Total capacity: 50,000mAh at 10.8V.</li><li>Total energy: 540Wh (50,000mAh × 10.8V).</li></ul></li></ul>With 6000mAh cells, the 3S10P battery pack achieves a 20% higher capacity (from 50,000mAh to 60,000mAh) and energy (from 540Wh to 648Wh), resulting in longer runtime for devices that prioritize endurance.<h3>Example 2: 13S4P Configuration</h3>In a 13S4P setup:<ul><li>Using 6000mAh Cells (XTAR 6000mAh):<ul><li>Each parallel group of 4 cells yields 24,000mAh.</li><li>Total capacity: 24,000mAh at 46.8V (3.6V nominal per cell × 13 series cells).</li><li>Total energy: 1,123.2Wh (24,000mAh × 46.8V).</li></ul></li><li>Using 5000mAh Cells (e.g., LG M50):<ul><li>Each parallel group of 4 cells yields 20,000mAh.</li><li>Total capacity: 20,000mAh at 46.8V.</li><li>Total energy: 936Wh (20,000mAh × 46.8V).</li></ul></li></ul>Here, using 6000mAh cells offers a 20% increase in both capacity and energy, from 20,000mAh (936Wh) to 24,000mAh (1,123.2Wh). This is ideal for high-voltage applications needing extended operation without frequent recharges.Across both configurations, opting for 6000mAh cells over 5000mAh cells results in a consistent 20% increase in total battery capacity and stored energy. This provides significant runtime benefits, whether in moderate-capacity (3S10P) or high-voltage (13S4P) applications, enhancing performance and efficiency in devices requiring sustained power delivery.<h3>Protection Board&nbsp;</h3>I have bad news. There is a problem with the above examples. One thing we don't like about this cell is that we can't seem to find any that don't have the protection board preinstalled. The protection board that helps prevent overcharging, over-discharging, and short circuits. While these boards are essential for safety, they can complicate configurations that require <a href="https://cellsaviors.com/blog/series-vs-parallel">connecting multiple cells in series and parallel</a>, as the protection circuitry isn't rated for the potential voltages that it will see when put in series.&nbsp;<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image/jpeg&quot;,&quot;filename&quot;:&quot;21700 protection board assembly.jpg&quot;,&quot;filesize&quot;:80919,&quot;height&quot;:260,&quot;href&quot;:&quot;https://admin.cellsaviors.com/storage/doCtotpJyMG49AYkYro2IvMTxMvKJeExNvnKB2eD.jpg&quot;,&quot;url&quot;:&quot;https://admin.cellsaviors.com/storage/doCtotpJyMG49AYkYro2IvMTxMvKJeExNvnKB2eD.jpg&quot;,&quot;width&quot;:568}" data-trix-content-type="image/jpeg" data-trix-attributes="{&quot;presentation&quot;:&quot;gallery&quot;}" class="attachment attachment--preview attachment--jpg"><a href="https://admin.cellsaviors.com/storage/doCtotpJyMG49AYkYro2IvMTxMvKJeExNvnKB2eD.jpg"><img src="https://admin.cellsaviors.com/storage/doCtotpJyMG49AYkYro2IvMTxMvKJeExNvnKB2eD.jpg" width="568" height="260"><figcaption class="attachment__caption">21700 protection board assembly.jpg 79.02 KB</figcaption></a></figure><h3>The Verdict</h3>So, what is the highest capacity 21700? In today’s market, the XTAR 21700 6000mAh takes the lead with the Vapcell’s F60 (6000mAh) and BAK's 5.5Ah (5500mAh) following closely. While the XTAR 6000mAh battery is readily available, it commands a premium price at over $15 per cell. For those seeking alternatives, Vapcell F60 and BAK 5.5Ah provide slightly lower capacities but offer competitive performance at potentially better prices.As 21700 battery technology continues to evolve, these high-capacity cells highlight the rapid progress in lithium-ion technology, making them ideal for high-demand applications such as EVs, power tools, and other devices requiring sustained power. However, it’s crucial to verify capacity claims, as some manufacturers may exaggerate figures beyond current capabilities. Presently, XTAR’s 6000mAh is the maximum verified capacity in this format, though upcoming advancements in battery chemistry and materials suggest that even higher capacities may soon be achievable. Oh, by the way. The reason the Vapecell is put second after the XTAR is because, well, it's a Vapcell and that company is known to produce knock-off cells and rewraps sold as new. For that reason, I’m going to have to pretty harshly doubt any capacity claims until we get our hands on some of them.

Learn step-by-step how to build a fast charge USB battery bank using the IP5328P module. Enjoy reliable portable power for your devices anywhere!

How to Build a Fast Charge USB Battery Bank Guide

Imagine this scenario: you're on a camping trip, miles away from any power outlet, when your smartphone's battery starts to dwindle. You reach into your backpack and pull out a <a href="https://cellsaviors.com/blog/diy-power-bank">sleek USB battery bank</a>. Within moments, your phone is charging, and you can continue capturing the breathtaking scenery and navigating your route without worry. This simple device, often taken for granted, underscores the importance of portable power solutions in our tech-dependent lives. Now imagine making one of those! How cool would that be?!In this article we will show you how to build a fast charging USB battery bank based on the IP5328P USB Battery Fast Charge Module.&nbsp;<h3>Why The IP5328P Dual USB Battery Fast Charge Module Is So Great</h3>The IP5328P Dual USB Battery Fast Charge Module is a truly great board. It can boost a single cell's voltage to 5V, 9V, or 12V, delivering up to 18 watts of power. It's an ideal tool for tech enthusiasts and DIYers aiming to build a dependable, fast-charging USB battery bank. Here are a few reasons why we think the IP5328P Fast Charge Module is the ideal solution for building a DIY fast charging USB Battery Bank:&nbsp;Ease of AssemblyHistorically, creating a fast-charging USB battery bank was complex, often requiring multiple cells, a <a href="https://cellsaviors.com/blog/bms-lithium-batteries">Battery Management System (BMS)</a>, and intricate wiring. The IP5328P&nbsp; simplifies this process dramatically. You can <a href="https://cellsaviors.com/blog/parallel-lithium-batteries">use a single cell or multiple cells in paralle</a><a href="https://cellsaviors.com/blog/balance-lithium-batteries-parallel">l</a>, connect them to the board, and you’re set. This simplicity not only makes it accessible but also significantly reduces the risk of imbalance and damage.Bi-Directional USB-C PortOne of the standout features of the IP5328P&nbsp; is its bi-directional USB-C port. This highly sought-after feature allows for both charging and discharging through the same port, significantly enhancing convenience and efficiency. Whether you're replenishing the battery bank or powering a device like a phone or tablet, the USB-C port ensures you achieve the fastest charging speeds available. While the USB-A ports on the side are useful, they do not support 20-watt fast charging. However, they are perfect for discharging the battery bank and charging other devices at standard speeds.User-Friendly IndicatorsThe IP5328P makes it easy to monitor your battery's status with its four red LED indicators, which provide a clear, real-time display of the remaining battery capacity. For instance, when the battery is between 75% and 100% charged, the first three LEDs will be solid, and the fourth will flash. During discharging, the last LED will flash when the battery is nearly empty, giving you ample warning to recharge.In addition to these indicators, the charger board includes a blue LED that lights up whenever fast charging is detected, whether you're charging the battery bank or using it to power another device. This blue light activates whenever the voltage exceeds 5V, offering a straightforward signal that fast charging is in progress.Versatility in Powering DevicesThe IP5328P isn’t just for charging phones and tablets. Its robust design allows it to power various devices like routers, small fans, and lights. While pushing the board to its limits may cause occasional power drops, it performs admirably within its intended range, making it an excellent choice for multiple applications.Reliable Performance with a Few ConsiderationsThe IP5328P&nbsp; is designed for reliability and performs admirably in most situations. Users have reported that the board does not overheat or suffer damage under normal use, particularly when fast charging devices up to its 18-watt capacity.However, when the board is used as a power supply for devices rather than a charger, it’s best to keep the power draw under 10 watts. Drawing more than 10 watts continuously might cause the board to temporarily lower the output voltage to maintain stability and prevent overheating. This safeguard is a testament to the board’s thoughtful design, ensuring both longevity and reliable performance.Incredible ValueAt an astonishing price of $13 for two boards, the IP5328P offers incredible value. For just $6.50 each, you get a high-quality, fast-charging module with three ports, easy-to-read status indicators, and exceptional reliability. Its flat bottom design makes it easy to integrate into custom cases, further expanding its usability.Specifications and PerformanceThe IP5328P&nbsp; can deliver up to:<ul><li>3.1 amps at 5V</li><li>2.4 amps at 7V</li><li>2 amps at 9V</li><li>1.5 amps at 12V</li></ul>While it doesn’t support 15V or 20V outputs, its performance within the 5V to 12V range is impressive and more than sufficient for most fast-charging needs.<h3>How To Build A Fast Charge USB Battery Bank</h3>Building Your Own Fast-Charging USB Battery BankActually building a USB battery bank with the IP5328P Dual USB Battery Fast Charge Module could not be easier. All you have to do literally is connect positive on the board to the positive of your cells and negative on the cells to negative on the board. You don't even need a BMS because there are no cell groups to balance, so you don't have to worry about balancing.The only concerns are over-discharge protection, over-current protection, and over-charge protection, and this board handles all of that. The board has a built-in BMS that does everything but balancing, which isn't needed when you have only one cell group. So it's very easy to build.The problem is you need a case for it. You could always just shrink wrap it together or tape it up really nicely and it will work well. You can pad it and cut little holes for the ports to make yourself a nice little USB battery bank. But if you want it to be really nice, solid, and professional looking, then you're going to need an enclosure.We have found a really great <a href="https://cults3d.com/en/3d-model/gadget/usb-power-bank-7-cell-design">case for the IP5328P USB Charge Module</a>, making building battery banks with it extremely easy. Using this case you can easily make your very own sturdy, and professional looking USB fast charge battery bank. For some reference, if you use 3.2Ah cells, that would result in a 22,400 mAh battery bank!&nbsp;<h3>Materials Needed</h3><ol><li>IP5328P Dual USB Battery Fast Charge Module</li><li><a href="https://cellsaviors.com/blog/18650-21700-best-option">Lithium-ion battery (18650 cell or similar)</a></li><li><a href="https://cellsaviors.com/blog/pvc-silicone-wire">Wires (preferably 18 AWG)</a></li><li>Soldering iron and solder</li><li>Multimeter</li><li><a href="https://cults3d.com/en/3d-model/gadget/usb-power-bank-7-cell-design">3D Printed casing</a>&nbsp;</li><li><a href="https://cellsaviors.com/blog/why-use-nickel-strips-for-battery-packs">Nickel strips</a></li><li><a href="https://cellsaviors.com/blog/best-spot-welders">Spot welder</a></li></ol> <blockquote>[[ aff type=aff ~ link=<a href="https://www.google.com/url?q=https://amzn.to/3yl0FWY&amp;sa=D&amp;source=docs&amp;ust=1723696035113333&amp;usg=AOvVaw2jSbiaPzka_6O-iNFaKMVu">https://amzn.to/3yl0FWY</a> ~ title=`IP5328P ~ image=https://admin.cellsaviors.com/storage//51qYI55BE0L._SL1050_.jpg ~ description=`IP5328P has a constant current, constant voltage lithium battery charging management system that supports a synchronous switch structure.` ~ height=small ~ buttonText=`Check price`&nbsp; ]]</blockquote><h3>Step-by-Step Guide</h3>Insert the Battery Cells: Place the lithium-ion battery into the bank bank core. Ensure the polarity is correct.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:281,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXdOIYpumhQruMDNXlp6Es_kwiF6XkZjKwe3o8DMamLI4PlWkgxroY-BbS9-59HPbI0H_Ux4t9RhTw-3Zd7qPC3t2ju3F4QavpTWPtzmc8dZVNUyIjaQJfHn3EEF9LEN6ZPtGo6Tuz8y2KnMBDmPxya3XT8?key=qJbtDAjRSPEMdF_Hq_2ZZg&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXdOIYpumhQruMDNXlp6Es_kwiF6XkZjKwe3o8DMamLI4PlWkgxroY-BbS9-59HPbI0H_Ux4t9RhTw-3Zd7qPC3t2ju3F4QavpTWPtzmc8dZVNUyIjaQJfHn3EEF9LEN6ZPtGo6Tuz8y2KnMBDmPxya3XT8?key=qJbtDAjRSPEMdF_Hq_2ZZg" width="624" height="281"><figcaption class="attachment__caption"></figcaption></figure>Solder Wires to Nickel Strip: Solder the positive (red) and negative (black) wires to the back side of the corresponding nickel strip before welding the nickel strips to the cells.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:281,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXfQ9_KE83Btodiw_jaVvIRhmsd77GI-PSjihVI3ty1tjfjLZvDEoJJNDzvo62DzB08Uih7blgkaWnZnsdkREGm1l0NXOFAUXPxpe9dgzpN_Sq4cNrSt1lC4F-i4OVl2TtBuDKAqlpJPMsGz8u1Z-0uE5bMX?key=qJbtDAjRSPEMdF_Hq_2ZZg&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXfQ9_KE83Btodiw_jaVvIRhmsd77GI-PSjihVI3ty1tjfjLZvDEoJJNDzvo62DzB08Uih7blgkaWnZnsdkREGm1l0NXOFAUXPxpe9dgzpN_Sq4cNrSt1lC4F-i4OVl2TtBuDKAqlpJPMsGz8u1Z-0uE5bMX?key=qJbtDAjRSPEMdF_Hq_2ZZg" width="624" height="281"><figcaption class="attachment__caption"></figcaption></figure>Weld The Nickel Strips:&nbsp; Slide the wires into the channels and then weld the nickel strips onto the cells. <figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:281,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXeWH7CSqLNgSP0TJUfZNu9pN-_d0KAkdY2MnZSBo0IsKFrKqURLHqfjMH_fA5uTVGrcWKK6j2OjTVJ6fiUjmzh37VeKa0OY-ptpfIFN5mDqpd_0FsDJowR2iII_ulBt_nDC7fobfgHv49ub4nACTslmBgy_?key=qJbtDAjRSPEMdF_Hq_2ZZg&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXeWH7CSqLNgSP0TJUfZNu9pN-_d0KAkdY2MnZSBo0IsKFrKqURLHqfjMH_fA5uTVGrcWKK6j2OjTVJ6fiUjmzh37VeKa0OY-ptpfIFN5mDqpd_0FsDJowR2iII_ulBt_nDC7fobfgHv49ub4nACTslmBgy_?key=qJbtDAjRSPEMdF_Hq_2ZZg" width="624" height="281"><figcaption class="attachment__caption"></figcaption></figure>Connect to the Module: Solder the positive and negative wires coming in from the channels to the terminals on the IP5328P module.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:281,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXcvczyonOhFxT1DaTvFuktejQWtDW2zAMzJ80VRDEfy-sM8j9PE5p3XY5bHMuhdEGUAC-64euFvXbqpSqPf6qVWZmJow07LkGbZmQQpRtmQKpy7RSaxqVJ5g9reyt9mraDhz7dwZ3IrIxvxKYhq3ly_2Iad?key=qJbtDAjRSPEMdF_Hq_2ZZg&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXcvczyonOhFxT1DaTvFuktejQWtDW2zAMzJ80VRDEfy-sM8j9PE5p3XY5bHMuhdEGUAC-64euFvXbqpSqPf6qVWZmJow07LkGbZmQQpRtmQKpy7RSaxqVJ5g9reyt9mraDhz7dwZ3IrIxvxKYhq3ly_2Iad?key=qJbtDAjRSPEMdF_Hq_2ZZg" width="624" height="281"><figcaption class="attachment__caption"></figcaption></figure>Install The Core Into The Casing: Slide the completed USB Battery bank core all the way down into the casing<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:281,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXeJAp9XDY6seqiahbfdRQbzYPEzdEMGfd2Je8nG2HEHMDU-QsRFCIa3Ij0bvlmiAhxkkbmddRC1XNaeqgv_ECmAhU6yWt8N7CsFdlho3R_MtvOl56ORN6oWOTk1vgQhgd52adk0Q0mUiIXANtnx02F9rS0?key=qJbtDAjRSPEMdF_Hq_2ZZg&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXeJAp9XDY6seqiahbfdRQbzYPEzdEMGfd2Je8nG2HEHMDU-QsRFCIa3Ij0bvlmiAhxkkbmddRC1XNaeqgv_ECmAhU6yWt8N7CsFdlho3R_MtvOl56ORN6oWOTk1vgQhgd52adk0Q0mUiIXANtnx02F9rS0?key=qJbtDAjRSPEMdF_Hq_2ZZg" width="624" height="281"><figcaption class="attachment__caption"></figcaption></figure>Secure The Casing Onto The Core: Use the 3d printed tool to install the included 3d printed screw into the casing through the core- locking it all in place.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:281,&quot;url&quot;:&quot;https://lh7-rt.googleusercontent.com/docsz/AD_4nXdMUWc5AM0VODFHY72swU1d5ifarHxmn3CGUkmQk0dYAzcemQKdT2DPuZT_gWnc-n4agkBVWIh7F10zSp57fE1VW4kasTP20H6GpNOKvPY4Rs2pzsOBSUmbWoySSZGvRYmiYA1q4UwUqdygo3zItYmgS5Ed?key=qJbtDAjRSPEMdF_Hq_2ZZg&quot;,&quot;width&quot;:624}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXdMUWc5AM0VODFHY72swU1d5ifarHxmn3CGUkmQk0dYAzcemQKdT2DPuZT_gWnc-n4agkBVWIh7F10zSp57fE1VW4kasTP20H6GpNOKvPY4Rs2pzsOBSUmbWoySSZGvRYmiYA1q4UwUqdygo3zItYmgS5Ed?key=qJbtDAjRSPEMdF_Hq_2ZZg" width="624" height="281"><figcaption class="attachment__caption"></figcaption></figure>Congratulations! You've officially made your first Fast Charge USB battery bank with the IP5328P Dual USB Battery Fast Charge Module. Enjoy your reliable and efficient portable power solution.<h3>Some Things To Consider</h3>Upon first connecting the board, it needs an initial charge to activate. This can be done via a USB port or power supply. Once activated, all three ports can be used simultaneously, even while charging the battery bank. However, it’s important to note that using the USB-A ports will kick the USB-C port out of fast charging mode.<h3>Conclusion</h3>The IP5328P&nbsp; Dual USB Battery Fast Charge Module is a remarkable tool for anyone looking to build a reliable and efficient USB battery bank. Its bi-directional USB-C port, user-friendly indicators, and robust performance make it a standout choice. Whether you're powering everyday devices or exploring more complex projects, this board provides the power and flexibility you need. With its ease of use and unbeatable price, the IP5328P&nbsp; is an excellent investment for your tech arsenal.

How To Build A Fast Charge USB Battery Bank

Explore how heat impacts lithium battery life, including effects from sunlight, high current, and low voltage, and learn tips to extend battery longevity.

Factors That Reduce Lithium Battery Lifespan: The Role of Heat

There are <a href="https://cellsaviors.com/blog/lithium-batteries-degradation">several things that can shorten the lifespan of a lithium ion battery,</a> but they all come down to heat. Heat is generated through several means and leads to a cascade of detrimental effects on the battery's chemistry and physical structure. The most common ways heat damages a battery are by leaving it in direct sunlight, running too much current for too long, or using the battery for prolonged periods towards the lower end of its voltage range. To extend the life of your lithium battery when not in use, learn the <a href="https://cellsaviors.com/blog/Extending-Lifespan-Lithium-Battery">best storage methods</a> from our other articles.<h2>Heats Effect on Lithium-Ion Degradation</h2>There are so many ways heat can affect a battery. Whether it's internally generated from an external source, heat is the primary factor affecting a lithium-ion battery’s overall lifespan. Something as simple as exposing a battery to direct sunlight for long periods of time can drastically shorten its lifespan. When a battery is left in direct sunlight, it absorbs energy from the sun, leading to an increase in its temperature. Another avenue is high current demands; drawing excessive current from a battery causes an increase in <a href="https://cellsaviors.com/blog/measure-internal-resistance">internal resistance</a>, which in turn generates heat.Also, low-voltage operations contribute to this issue. As the battery discharges and its voltage drops, the internal resistance increases, further elevating the temperature. These factors combined can significantly impact the efficiency and safety of lithium-ion batteries.<h3>Chemistry &amp; Heats Impact on Battery Lifespan</h3>Lithium-ion batteries, based on complex chemical reactions, are highly sensitive to temperature variations:<ul><li>Chemical Instability: The chemistry of lithium-ion batteries is inherently unstable and temperature-dependent. Elevated temperatures can disrupt these chemical processes, leading to efficiency losses and potential hazards.</li><li>Resistance and Heat: Electrical resistance in batteries increases with temperature. This increase in resistance can create a positive feedback loop, further raising the temperature and exacerbating the problem.<figure data-trix-attachment="{&quot;contentType&quot;:&quot;image&quot;,&quot;height&quot;:321,&quot;url&quot;:&quot;https://lh7-us.googleusercontent.com/docsz/AD_4nXeFjTgqkBraytx_u7gCjItP2wxld9pvxxIwDvXf3Dr-9q_kXA0HlcCX9vOSPjT9zY00SirD6ZaVquZi7QPiaYNnjv9w40OuQGnwdnO1wcZ72EkxedYplnMcp8o8ZubH07_zzRtz1NXqS36WKt0rjgA3UZXM?key=_qEVNkeeDb2kJmp5uy3-8w&quot;,&quot;width&quot;:577}" data-trix-content-type="image" class="attachment attachment--preview"><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXeFjTgqkBraytx_u7gCjItP2wxld9pvxxIwDvXf3Dr-9q_kXA0HlcCX9vOSPjT9zY00SirD6ZaVquZi7QPiaYNnjv9w40OuQGnwdnO1wcZ72EkxedYplnMcp8o8ZubH07_zzRtz1NXqS36WKt0rjgA3UZXM?key=_qEVNkeeDb2kJmp5uy3-8w" width="577" height="321"><figcaption class="attachment__caption"></figcaption></figure></li></ul><h3>Internal Resistance and Its Consequences</h3>Internal resistance plays a pivotal role in how heat affects lithium-ion batteries:<ul><li>Resistance Measurement: A typical lithium-ion cell has an internal resistance ranging from 15 to 30 milliohms.</li><li>Heat Generation: Current flowing through this resistance generates heat. For instance, 3 to 5 watts of heat loss in a battery can significantly increase its temperature, reducing its lifespan.</li></ul><h2>Voltage Level Considerations</h2>Voltage levels within a lithium-ion battery also influence its thermal behavior. As the voltage drops below certain levels (below around 3 volts), the internal resistance increases, causing more heat generation and accelerating battery degradation.&nbsp; So, however much heat your battery generates under a 30 amp load when it's fully charged will be a whole lot different than the same load when the battery is almost dead.<h2>Extending Battery Life</h2>Lithium-ion batteries function through the movement of lithium ions between the anode and cathode in a solvent, typically lithium salt in an organic solvent. Charging a battery moves the ions to the anode while discharging them moves them back to the cathode. This process is susceptible to wear and degradation from heat, high voltages, and deep discharges.Here is a basic run down and some things you can do to extend the life of a lithium-ion battery:<h3>1. Optimal Charge Levels</h3>Do Not Fully Charge or Deep Discharge: It’s <a href="https://cellsaviors.com/blog/maximum-charge-voltage-of-12v-battery">best to charge lithium-ion batteries to about 80% and not let them drain below 20%</a>. This helps in avoiding the stress that full charges or deep discharges can impose on the batteries. Battery University studies have shown that partial discharges, with occasional full discharges for calibration, can significantly extend battery life.<h3>2. Appropriate Charging Practices</h3>Use the Right Charger: Always use a charger that has the correct voltage and current that your battery needs. Using non-compatible chargers can affect charging cycles and degrade the battery.Avoid Fast Charging: Constant use of fast chargers can degrade lithium batteries quicker. Fast charging works by increasing the voltage, which can heat up the battery and accelerate degradation.<h3>3. Temperature Management</h3>Keep Batteries Cool: Store and charge batteries in a cool environment. High temperatures cause lithium-ion batteries to degrade much faster. According to research, a lithium-ion battery operating at 25°C (77°F) will have a longer lifespan compared to one operating at 40°C (104°F). Find out <a href="https://cellsaviors.com/blog/charged-or-uncharged-lithium-battery-storage">if it's better to store lithium batteries charged or uncharged&nbsp;</a>by checking our detailed guide in another article.Avoid Cold Temperatures: Just as high temperatures can degrade batteries, exposing them to too cold temperatures can cause permanent damage, especially if charged while cold. The optimal storage temperature for a lithium-ion battery is around 15°C (59°F). Discover <a href="https://cellsaviors.com/blog/lithium-batteries-warm">ways to keep batteries warm</a> by exploring our tips in other articles.<h3>4. Avoid Deep Discharges</h3>Charge Before Empty: Lithium-ion batteries do not have a memory effect, so there is no need to fully discharge them before recharging, as was necessary with older battery types. Deep discharges can strain the battery; hence, charging periodically and making sure to discharge to no more than 20% is optimal.&nbsp;<h3>5. Handling and Care</h3>Physical Protection: Avoid dropping or physically stressing the battery. Physical damage can lead to internal shorts, leading to battery degradation or failure. For <a href="https://cellsaviors.com/blog/lithium-cell-battery-safety">lithium-ion battery safety tips</a>, check out our detailed articles covering essential precautions and concerns.Use Battery Cases: If possible, use a protective case for batteries, especially for those used in harsh environments to avoid mechanical stresses and punctures.<h3>6. Proper Storage</h3>Long-Term Storage: If <a href="https://cellsaviors.com/blog/lithium-battery-storage">storing a lithium-ion battery</a> for a long period, charge it to about 50% every six months to maintain battery health and prevent it from going into a deep discharge state.<h3>Finding the Perfect Trade-Off</h3>Balancing battery usage and preservation involves finding a middle ground:<ul><li>Charge-Discharge Levels: Charging to 80% and discharging to 20% can extend the battery's life by 2.5 to 3 times while sacrificing some capacity.</li><li>Watt-Hour Efficiency: This strategy, while reducing immediate capacity, increases the total watt-hours extracted from the battery over its lifespan.</li></ul>Heat is the primary factor that shortens the life of lithium-ion batteries. By understanding and mitigating the sources of heat generation, such as exposure to sunlight, high current demands, and low voltage operation, the lifespan of these batteries can be significantly extended. Managing the internal resistance, optimal charging, and discharging practices are key to preserving the health and efficiency of lithium-ion batteries, thereby enhancing their longevity and overall performance in various applications.It’s important to remember that charging, discharging, and even storage are part of the heat cycle for lithium ion batteries. The closer you <a href="https://cellsaviors.com/blog/best-battery-storage-voltage">keep your battery to room temperature</a>, the longer its going to last.&nbsp;

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