Max battery current

Is there a way to test the maximum current that your battery can handle

Try to determine what current causes a 10% drop in voltage and that is the generally accepted maximum current.


Let’s start from the ground up, what type of battery do you have?


As continues value?

Yes for continuous.

Obviously the better option is to just check the cell specs, but I am guessing the cells are unkown to OP.



yeah ;



Let’s pretend he’s got a black box and battery power comes out of it. How does he test what the max current might be?

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If it’s not a sealed pack, just cut the shrink wrap and check what’s written on the cells?


they are probably fake

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Spin up a motor in VESC tool, see what the battery amps are and what the voltage drop is and extrapolate.

Since I am guessing OP does not have access to a proper DC electronic load.

Where did you buy this thing? Even if it’s fake chances are someone has had experience with the same one.

What’s the branding?

Look up how mooch tests cells. Mostly to do with temperature. If you can measure how hot the cells get, a continuous draw would theoretically never put the cells past 80C without additional aasisted cooling… Better question is, what tools do you have at your disposal for testing this pack?

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Reviving an older thread, assume it’s ok to keep apples with apples and not pollute with such a similar topic.

Battery is a 12s3p 21700 P42a as per piccie above.

like everyone in the history of ever, I’m trying to squeeze a bit more out of this pack (without doing too much damage to it) and I just don’t understand VESC settings enough…

The question is, if the pack is rated for 135A as per the battery calculator, and assuming the Battery Current Max is each side, can I whack it up to 60a (each side) with a comfort zone left in place of 15A?

Am I missing something here or just thick?

At 3p i’d recommend sticking to 75A. If you absolutely must squeeze more, 90A should be ok.

@glyphiks as in set battery current to 25A and not the 45A where it currently is?

Motor amps are currently on 90A

I’m only noticing any sag at about %30

The 45 battery amps per side is a total of 90A, the 25A i am referring to is what I default to per cell in parallel.

If you choose to go higher than 90A total (30A per cell in parallel) it would be wise to be monitoring the temps of your cells.

I wouldn’t go higher than 30A per cell, even for my own curiosity. Cells aren’t cheap.

Maybe try boosting your motor amps and see how that works for you instead. But again, wise to monitor motor temps as well.

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