Hooking different capacity batteries 272ah and 280ah in series

[Dave (Boog)]

I have 8 each Lishen 272 ah and Eve 280 ah cells that I want to use together to make one 48 volt battery. I'm pretty sure that I can't just connect them all in series and use a 16s BMS. But can I create two 24 batteries each with their own BMS and connect the two batteries in series to make a 48 volt battery?
Will this work? Other than having separate BMS is there anything else to look out for or should I sell the 8 Lishens and buy 8 matching EVE cells?
Any comments are appreciated.

 

[Solar388]

I did connect 8 280aH and 8 304aH together to form a 48V on a 16S BMS. It worked fine from what I could tell the short amount of time I used it that way. I had read that the BMS will handle balance, and the balance is based on a low and a high voltage, not the aH of discharge and charge.

 

[Dave (Boog)]

I did connect 8 280aH and 8 304aH together to form a 48V on a 16S BMS. It worked fine from what I could tell the short amount of time I used it that way. I had read that the BMS will handle balance, and the balance is based on a low and a high voltage, not the aH of discharge and charge.

Thanks for the comment on your experience with connecting different ah batteries in series. I was not sure if you could do it with a single 16s BMS or not. I guess I can give it a try and see how it works. I do have two 8s and a single 16s BMS. One thing I was not sure about was the internal resistance of the cells, I know that the Lishen and Eve cells have different IRs, so not sure how that figures into whether they play nice together or not.

 

[Alkaline]

different capacity should only be done in parallel and not series otherwise your whole bank will be limited to the smaller capacity.

but with parallel you can get all the powa from the batt.

 

[Dave (Boog)]

different capacity should only be done in parallel and not series otherwise your whole bank will be limited to the smaller capacity.

but with parallel you can get all the powa from the batt.

I was aware about the loss in capacity, however, I only have the two different types of cells and I already have purchased all of the equipment, Inverters etc. to use for a 48 volt system, so I plan on staying with a 48 volt system. In order to use the cells in parallel and stay with 48 volts, I would need another 16 cells. I don't mind losing the 8 ah that I will lose by connecting them in series.

 

[shanemgrey]

I searched here before posting, but didn't find your thread until it showed in "similar threads" after I posted my question which is essentially the same thing with 280 and 304ah cells.

It sounds like the answer is that there is no problem other than the capacity difference is wasted. The weakest cell in series will be the limit as they all get drawn down at a similar rate and the one of the lower capacity ones will hit low voltage cutoff before the higher capacity ones can be fully utilized.

Did you end up building it as with a 16S BMS? Any issues?