After learning about battery safety and how to choose a BMS, the next logical step is to find out where to find lithium batteries. The good news is that lithium-ion batteries are not hard to find. They are in just about any portable electronics and are commonly for sale on many online marketplaces. 

Lithium-ion battery cells can be harvested from several places to build a battery pack. If you are not wanting to do the work in harvesting old lithium-ion battery cells, there are several places online that you can buy them from. Complete lithium-ion battery packs can be purchased on Amazon and eBay, but don’t expect to get the highest quality battery packs from those places. Given the current environment, it’s still best to either custom-build your own lithium-ion battery pack or have a professional battery builder do it for you. 

In this article, we will go over all the various things you need to know and look out for when shopping for lithium-ion battery cells or lithium-ion battery packs. We will also touch on where not to get lithium-ion battery cells. 

Where Are Lithium-ion Batteries Most Commonly Found? 

All over the place! Specifically, lithium-ion batteries are found in laptops, cell phones, ebikes, USB battery banks, automobiles, fitness trackers, and just about anywhere else you need portable power.

Lithium Ion Battery Harvesting

You can find totally healthy lithium-ion battery cells in several readily available products. A quick search of Craigslist or the Facebook marketplace will reveal a high number of old laptops that have lithium-ion battery cells in them.

When a laptop battery pack goes bad, it's generally only 1 cell that actually has a problem. So, that means that there are 2 to 5 totally good lithium-ion battery cells in most laptop battery packs.

Another great source is old modems. For quite a while it was commonplace for cable modems to have a small built-in battery backup. Most of the time, the battery pack in these modems never got fully cycled. So, if you are wondering where to find lithium batteries, modems are a great source.

Where To NOT Get Lithium Ion Battery Cells

Lithium-ion battery packs can be found all over the place. There are some places, however, that are not worth looking at. Pretty much any drill that is not brand new is not going to have lithium-ion batteries. You will sometimes get lucky and find a broken drill that has a lithium-ion battery. More often than not, though, lithium-ion-powered drills are not old enough for many of them to be discarded yet. 

So, the overwhelming majority of drills in circulation today still have the old NiCd batteries in them. This makes drills an excellent candidate for an upgrade to lithium-ion batteries, but they are a poor choice for lithium-ion harvesting. 

Also, in most cases that a drill is discarded, there is nothing wrong with the drill anyway. It’s usually just the battery pack that has failed. So, even if you get lucky and get your hands on a newer drill, the lithium-ion battery cells in that drill will be closer to the end of their usable lifespan.

Remember, drills are high-current devices. While it’s true that drills are not operated for very long continuously, when they are operated, it's at very high current levels. This places extra strain on the cells, so even if you end up with a few decent cells harvested from a lithium-ion drill battery pack, using them could be one of the quickest ways to start lithium-ion battery fires or even a lithium-ion battery explosion. 

Where To Find Lithium Ion Battery Packs

Complete lithium-ion battery packs can be found at the usual places online such as eBay and Amazon. Lithium-ion battery packs found on these websites are readily available and are often priced to sell as quickly as possible. 

While it's true that one can certainly buy one of these lithium-ion battery packs and have no problem with it, the buyer is seldom actually getting what they are paying for. As a rule of thumb, it's good to subtract about 25% from the rating capacity of these battery packs to get closer to the actual figure. 

So, if you buy a 20Ah battery pack on eBay, expect it to provide around 15Ah of capacity. This is the unfortunate culmination of rock bottom, highly competitive pricing, and the rampant pervasiveness of fake and improperly listed battery cells

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Shopping Criteria For Lithium Battery Cells

When shopping for the best lithium battery cells for your application, there are a few important things to keep in mind. 

  • Physical Size
    Lithium-ion battery cells come in all kinds of sizes. There are 18650s, 21700s, 32650s, and several other less popular formats. A battery pack that will barely fit X number of 18650 cells will not be able to fit nearly that many 21700 cells.  
  • Lithium Ion Battery Voltage
    Lithium-ion battery cells come in several varieties that have different voltage ranges. For example, your average run-of-the-mill lithium-ion battery cell will have a fully charged voltage of 4.2 volts and a dead voltage of around 2.5. Lithium phosphate cells, on the other hand, are fully charged at 3.3 volts and are dead at around 2.8. 
  • Max Change and Discharge
    It’s of critical importance to make sure your lithium-ion cells are able to support the load that you plan on putting them under. 

Shopping Criteria For A Lithium Battery Pack

When shopping for the best lithium battery for your application, there are several factors to take into consideration. Overlooking these things or not giving one aspect enough thought could at best leave you with buyer’s remorse, and at worst, put you and your family at risk. Lithium-ion battery safety should be taken very seriously when shopping around for a pack. 

  • Physical Size
    Make sure the lithium-ion battery you are looking to buy will physically fit in the location you plan on putting it in. 
  • Connectors
    Ensure that the lithium-ion battery pack you are looking at has the correct charge and discharge connectors for your application. 
  • Lithium Ion Battery Voltage
    Make sure that the battery pack you are wanting to buy supports the voltage range of the device you are wanting to power with it. 
  • Charging Speed
    Look into the maximum charge rate of the lithium-ion battery pack that you are considering buying. 
    If the battery fits all of your other specifications but takes too long to charge, it could be a deal breaker. If you charge a lithium-ion battery pack faster than what it is rated for, it could overheat and cause a fire. 
  • Charge Cycles
    Lithium-ion battery packs are rated by the number of charge and discharge cycles. Generally speaking, a lithium-ion battery pack is good for 500 to 800 full cycles before there is any loss of capacity.

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What Is The Cost Of A Lithium Battery?

There is no single answer to that question. There are many different types of lithium-ion battery packs, and those battery packs are made up of many individual lithium-ion battery cells. So, as you would expect, prices differ. In order to remain competitive, lithium-ion battery manufacturers do their best to keep prices as low as possible. 

The cost of the cells, however, is but one of several price-driving factors. There is also the cost of the conductor used to connect the cells, and also the cost of the wire used to make the external connections. Let’s not forget about the cost of the BMS module, and there is also a non-significant amount of tape and PVC wrap used in the process of building a lithium-ion battery. Another thing to consider is the cost of the charge and discharge connectors themselves. 

And that is just material cost. These things cannot simply assemble themselves. They instead have to be put together by a human being, and that process also has a cost. 


Whether you are looking for lithium-ion battery cells or lithium-ion battery packs, there are several sources to choose from. 

Lithium-ion batteries can be harvested from several viable sources to build a battery pack. Lithium-ion battery cells can also be purchased individually from several online vendors. When it comes to complete lithium-ion battery packs, those can be found on Amazon and eBay. It’s important to keep in mind, however, that bottom-dollar battery packs are one of the best examples of ‘getting what you pay for’. When it comes to a complete lithium-ion battery pack, it's always best for it to be custom-built to fit its specific use case.  

We hope this article helped you learn more about where to find lithium batteries. Thanks for reading!