Replacement 10s bms with 13s bms

Batteries, Chargers, and Battery Management Systems.
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knutselmaaster   100 W

100 W
Posts: 267
Joined: Apr 05 2014 6:50am
Location: near Paris, France

Replacement 10s bms with 13s bms

Post by knutselmaaster » Nov 30 2015 5:35am

Hello fellow ebike fanatics, I have a problem and I would appreciate your help :)

I had bought a 10s battery from bmsbattery.com that was not working well, it shut off whenever the bike vibrated.
I opened it and after some research I discovered that the problem had to be the bms, as all connections were OK and a little "tapping" on the bms made it shut off.
As I found the soldering of the bms very ugly, I resoldered everything but that did not seem to help.
So I contacted bmsbattery.com who kindly sent me a replacement bms.
The replacement bms is the same, but (there is always a but) it is not the 10s version, it is the 13s version...
They supplied the (14 wire) connector too.
When comparing the two bms there's not much difference, it is the same pcb with elements soldered on the 13s model that are empty on the 10s one and the temperature sensor is placed a little bit further, to include the added circuitry.

So here is my logical question:
Can I use the 13s bms on my 10s battery pack, by just connecting the first 11 wires and moving the temperature sensor to the right place?

this is the bms
Attachments
sketch-1448879641884.jpg
These are the differences

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Nobuo   10 kW

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Location: Madrid

Re: Replacement 10s bms with 13s bms

Post by Nobuo » Feb 12 2016 4:04am

All the balancing wires need to be connected, those 3 missed connections will make the BMS think that 3 series are under-voltage, so there won't be output power through discharge port. There are some boards customizable in the number of series used, but not that ones.
It is not common to have cuts just because vibrations, the issue could be seen visually. You could try first to bridge the thermistor (the white temperature switch) just because it is a mechanical device that could fail and make the cuts
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knutselmaaster   100 W

100 W
Posts: 267
Joined: Apr 05 2014 6:50am
Location: near Paris, France

Re: Replacement 10s bms with 13s bms

Post by knutselmaaster » Feb 12 2016 4:14am

Thank you very much for your reply.
I will try the bridge, if it it the cause of the problem I can simply replace it with the one from the 13s board. That will be a cheaper solution as ordering a new one (including shipping and taxes)
As I have resoldered almost every other part of the board with no result and did a really thorough check with a magnifying glass without any result, you might be right.
Stupid of me that I haven't tried that before...

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