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Mixing different capacity cells in same pack
#1
Hi
I'm building a 14s60p battery from 18650s - mostly from recycled e-bike batteries. I know that I will have to 'balance' the 14s packs so that the overall capacity of each pack is roughly the same, but what I'm wondering is how much can the capacity of each CELL vary - within one pack. For example, currently I have enough cells to make the battery, but my best cells vary from 2500 to 3500 mAh. My question is: provided I use rePackr to arrive at a distribution of cells that makes each of the 14s packs roughly of equal total capacity, will it be OK to have such a wide variation between cells within any given pack? 

For context, the battery will be used for home solar energy storage, and I'm not expecting to draw more than 60A (@48v) from the battery at any time.

Thanks!
BarryG
Not much in life is free these days - but Solar Energy is!
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#2
Mixing 2500mAh and 3500mAh is not a problem in this case.

One thing to keep in mind is that the current flow from/to each cell will differ. Eg. if you parallel a 1200mAh cell and a 2400mAh, the larger cell will draw/supply about 2x the current of the smaller one.
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#3
(09-28-2019, 11:17 AM)ajw22 Wrote: Mixing 2500mAh and 3500mAh is not a problem in this case.

One thing to keep in mind is that the current flow from/to each cell will differ.  Eg. if you parallel a 1200mAh cell and a 2400mAh, the larger cell will draw/supply about 2x the current of the smaller one.
Thanks for the comments, ajw22.....
ajw22 likes this post
BarryG
Not much in life is free these days - but Solar Energy is!
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