Any issues with creating an "unbalanced" Li-Ion pack?

Hi Everyone,

Haven’t seen this one come up on the forum, but something I’ve been thinking about. Is it possible to have a 10S 2.5P for instance?

So basically if I have 25 cells, but want 10s. Some of the cells would be 2 in parallel and other would be 3. I can’t think of any reason why this wouldn’t work. Balance charging through a bms should still be the same. Would the groups of 3 cells having more amp output screw anything up?

Just thinking this would be a decent option to get a little more range and use all the cells I have available.

A better option would be to buy 5 more cells and make a 10s3p

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the smaller groups would run empty faster. Without a bms this may damage the cells, with a bms you won’t utilize the full power of the pack and also shorten the smaller pack’s cycle life.

Just get 5 more cells for 10s3p

Got it. So basically the main downside would be you could never use the capacity of the 3p cells as the BMS would cutoff when the 2p reaches cut-off. So essentially it is like having 2p and the extra cells are just dead weight.

correct. hitting the low voltage cutoff for the bms is bad for cycle life as well

That settles that. Thanks!