10S4P Wiring Diagram, Bypass BMS, Does this look right?

Building a 10s4p and want to use the BMS for only charging as it is rated for low amps.

I haven’t bypassed a BMS before, so wanted to verify if I’m supposed to wire the dotted line in my diagram or not.

Also, I didn’t want to have a super long row of 20 cells x2 (these are 26650 cells), so I thought this layout, while wider, would be more space efficient. How have you guys arranged your 10s4p? Just wondering if there are any other alternatives out there.

I think I got the rest down, since I did do a 6s2p with a BMS before, but any other tips are appreciated!


Wouldn’t the dotted line provide the ground, for the cells, while the charger is plugged in?

Looks good, just make sure your breaker is anti-spark. the main B- may depend on how the BMS is wired.

Yeah, but connection 0 also goes to negative, so that’s why I’m not sure if B- is negative.

Thanks, do you know how to test this? connection 0 goes to negative, so I’m not sure if that is used for charging and B- is only for the discharge…Not really sure how to go about testing it

B- isn’t for discharge, only P- is. I think you’ll need to use it to balance charge correctly.

So the dotted line has to be wired or the battery wont balance charge properly

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@Jinra i’m interested to know this as well.

It depends on the BMS, some will charge fine, some won’t.

Would it be possible to do the series connection with 0.15mm nickel strips? How many would I have to use for each series connection?

Depends on how many amps you are trying to supply.