Connect two 12S Packs with different Ah in parallel


I’m not really findig a clear answer

Let’s say I have 2 Batteries
Both are 12S
Both are made with the same cells
1st Pack is 8P
2nd Pack is 14P

Would it be possible to
1 connect them directly
2 put something in between to connect them?

If 2, what is this thing called?

You trying to make a 12s22p?


a buck step-down converter, that takes 14s voltage and drops it to 8s.

or a voltage step up, that takes 8s voltage up to 14s voltage

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for multiple day rides

BOTH are 12S = same voltage

1st is 8P 2nd is 14P = different Ah

put the two batteries in parallel. They’re same voltage so it’s fine. Same reason you don’t do anything special adding more ‘P’ rows to battery you’re building.

will they get to 0% the same? or will the bigger one still have some Ah left? -> won’t the smaller one get discharged too low and take damage?

You can connect them in parallel for a 12s22p pack and it will discharge fine

If you connect them in series it will be about 100V and melt everything…do not do that

To charge it you’re gonna need to bridge the p-packs so they balance or use 2 BMSs


No, they will remain at the same voltage at all times. Charging is problematic though. You would need two BMSes.

They will provide an unequal amount of amperage, the bigger providing more and will discharge at the same time.

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For Series I know, but that wouldn’t make much sense anyway for current eSkates
for charging i would anyway use 2 BMS so that’s fine

Connect in parallel, not series

They will always have the same total voltage so they will get to 0% t the same time

I know. What’s your point?

Ok, good so far

How about I have 2 packs BOTH 12S

1st has 30Q cells 2nd has 35E cells

i guess that would still work, as it only changed the Ah?

Absolutely not, never mix cells in a battery

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sorry, understood your answer wrong
thought you meant: no, you can’t double the voltage

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but why? i mean if they’re on the same voltage?

All you need is here already

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I mean you can try but the cells with the lease internal resistance will take the brunt of the amp draw and degrade quickly