18650 Battery Pack Calculator and Planner

Select a cell from the cell database

Use this autocomplete search functionality to find your specific cell in order to pre-populate the values that we have for that cell.

This list is by no means exhaustive. If you have cells that you would like added or find that we are missing data for some of the cells that we do have, please email us, or fill out a contact form.

Cell database made possible and initially compiled by Wolf @ the SLS.com forums

Enter your cell manufacturer or model number to search for your cell. Results will appear automatically as you type.

Single cell information

Enter information on a single cell into the input fields to receive results for a single cell. Results will automatically generate every time a value changes and there is enough information to calcualte results.

The C-rate will be used down below at pack level calculations, so make sure you fill this section out.

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Enter the voltage of a single cell in your planned pack and the rated & tested capacity of one cell.

Enter the C-rate & the charge/discharge current.

Pack level information

Enter information related to your up-and-coming pack to get all kinds of information on the pack.

The C-rate, voltage, and capacities from the single-cell step will be used to calculate information in this step. Make sure that you fill out the fields above to get accurate results in this section.

You can learn more about wiring batteries in series & parallel configurations in the context of a battery pack by visiting these posts.

If this is your first time planning out a battery pack, check out our guide on how to build an 18650 battery pack .

Enter the intended series and parallel cell numbers of the pack you are going to be building.

Virtual battery life calculator

This section allows you to get an idea of approximately how long the battery life of the pack you are building will be. For now this calculates battery life at a fixed load amount, if you have ideas on how we can improve this calculator's functionality fill out a contact form and let us know!

For example If you plan on running something that consumes 1000W and your battery pack is 1kwh you can now estimate the life of the battery at a given load in watts.

Enter the amount of watts you expect to be drawing off of the pack to figure out how long that pack would last before needing a recharge.

Pack weight and cell cost

This section estimates the cost and weight of the pack based on cell count, single cell weight, and cost per cell.

The series and parallel information from the above step are used to calculate this information, so make sure you fill out the above step first.

Keep in mind that you'll also need to add a BMS to your pack, so that will add to the overall cost and weight. Check out this post we wrote to learn about choosing a BMS for your lithium ion battery pack.

Enter the weight per cell, in grams, and the cost per cell to calculate overall pack weight and cell cost.