LiPo battery pack, 2 puffy cells

Hello,
I have a 10s1p battery pack and 2 of the cells have gone bad (puffy) — 3.7v 6.4ah 230wh.

I’m getting conflicting answers on if I can just remove the last two cells, leave the last 2 battery leads disconnected, and still be able to run my ESC.

Dumb questions:
Does my ESC need 10x 3.7v to run correctly or can I just use 8?
For the 10s BMS, what is the rated A for this pack?
How do I find out the discharge rating C of these cells?

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8S is fine. I’m running 6S rn

your speed, range and power will be less.

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You could technically run fine on 8s but you’d have to replace your BMS, it wouldn’t like having two disconnected cells

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If buying a new 8s BMS - what’s the max A I should look for to support these cells? I see 20a, 25a, 32a, etc.

Were you running it in the discharge configuration before?

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I wish I could answer that… :frowning:

This 10s1p is straight from my board so it would be factory setup. Would there be anything I can look at on my board BMS/ESC or cables that gives away this answer on discharge?

Oh hmm what are the connected wires on the bms, are they labeled?

The thicker 16AWG black cable connects to P-
The thinner black cable connects to C-

I think that’s an XT60 plug for power (?) and the small red one I’m not sure (power switch?).

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Small red is for the charging port.

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Hmm well there’s three wires coming out it looks like, so probably it is wired for discharge… Maybe you could look up the part number and see if you could find the bms to see what kind of discharge rating it has

I found the manufacturer website but had no luck finding the part. It’s in Chinese and from Google translate the website seems to be for wholesalers.

I’ve got some spare time this evening… Should I attempt to move the cells together for 8s, leave the last 2 balance cables disconnected?

I recognize my lack of skills on battery building and that battery building can be dangerous…any caution / advice?

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Might be this one, but no product description.

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I don’t think just disconnecting two battery balance leads is a good idea, I think it would mess it up

It’s possible that the BMS would be confused and try to pull down the other cells, honestly not super sure.

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I think @Scepterr has tested using a higher s bms with lower s pack and it worked.

I don’t know about the charger though. I’m guessing you have a 10s charger. It would freak me out plugging a 10s charger into a 8s pack.

He could unpopulate the 2 now unused circuits to make the bms believe it’s an 8s bms? Or is there a software side to making that happen? I see so many Chinese bms have unpopulated series and always wondered if I could populate them to have a bigger bms rather than buying the exact same one with more populated circuits
Image to visualise what I mean by bigger bms with unpopulated circuits


@Gamer43 kai you’d be my go to person for a random question like that

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Some BMS you can leave the two most positive series packs disconnected

Some BMS you can leave the two most positive series packs disconnected but you need to short them out

But if you try it, make sure it’s the two furthest from B-

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It would depend on the exact BMS. I don’t think these BMS come with a user manual though…

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Thanks all for your input!

@BillGordon The PCB backing on my 10s BMS from the same company looks a little bit different. Could be a previous generation?

Does the “60” in the product name imply 60A?
3.7v x 6,000mah x10 cells in series = 60A?

Should I be looking for a 30V 48A 8s BMS that matches the cells (3.7v x 6,000mah x8 cells)?

@Excess I believe the charger is 10s (should I be looking for 37v output on the charger to confirm)?

@Gamer43 I checked the website and couldn’t find a user manual

@b264 How do I go about shorting two most positive balance leads shorted?

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Related question:

Can I use these cells to make a new 10s battery pack with my original 10s BMS? They fit the dimensions required in the cavity of the board, which was hard to find, to be honest.
3.7v 6,000mah discharge (1C)

I want to explore all the options of reviving my board with a new battery pack before giving it up for parts. I’m being optimistic and taking this opportunity to learn the basics of LiPo battery and battery building. I appreciate the help from the community.

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You don’t want to mix li-ion cells of different ages, but I’m not sure on pouches. I’m guessing frowned upon, but need a smarter guy like @ShutterShock to weigh in.

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