- #1

YoshiMoshi

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- TL;DR Summary
- Mix 21700 and 18650 cells in parallel?

I'm doing a 3S3P pack. My box can hold 9 18650s. It can also hold 3 18650s and 6 21700s. Is it ok to mix 18650s and 21700s in the same p pack? I would use the same 21700s and the same 18650s in each p pack. I would arrange them to maximize capacity.

So say 18650 cells are Model A cells (making up model number her for discussion purposes). All 3 18650 cells in my battery be model A.

The six 21700 cells are Model B cells.

One P pack would contain 2 model B 21700 cells and 1 model A 18650 cell.

I make three of these identical P packs described above. I would then put these P packs in series to create my battery pack.

Good idea? I don't see any issues. Each P pack would have roughly the same capacity and max current draw as each other (each cell slightly different even from same model) and would be identical.

So say 18650 cells are Model A cells (making up model number her for discussion purposes). All 3 18650 cells in my battery be model A.

The six 21700 cells are Model B cells.

One P pack would contain 2 model B 21700 cells and 1 model A 18650 cell.

I make three of these identical P packs described above. I would then put these P packs in series to create my battery pack.

Good idea? I don't see any issues. Each P pack would have roughly the same capacity and max current draw as each other (each cell slightly different even from same model) and would be identical.