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#57968
Hey folks,

so I got this battery recently. It is from a Tier scooter -- a Swap Battery Ninebot NFBP4814B 13INR22/71-3.

My multimeter shows no significant voltage at the cables. I assume that the BMS need to be activated. Does anyone know how to do it?

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#57998
I made some progress:

If I connect the black wire (GND) to the white wire, the multimeter shows shortly after 48V but drops it after 2-3 seconds. I guess this is something like an activation line? Maybe the yellow and green wires expecting some (CAN?) messages to actually activate the power output persistently? Any ideas?
#58000
About that battery: The whole scooter runs on a CAN bus, and as such, the battery needs to be activated via that bus.
Normally, this is how the thread would end.

However, I am reverse-engineering one myself, so here's what I can tell you so far:
The whole battery is cast into a brittle silicone, so it's 100% waterproof and an absolute b*tch to open. I spent a whole day on it.

Luckily, they didn't secure the STM32G0B1 (that is the main microcontroller) and even left a debug header on the PCB.
This means I was able to dump the firmware, and I'm currently working on reverse-engineering it, as soon as I know how to talk to it via CAN, I'll post an update.
#58005
Amazing! Thank you for clarifying.

Btw.. CAN has no "ground". CAN is a differential signal. You only have / use CAN high and low. I think the white cable is the activation line.

Can you please share the firmware dump with me. I would like to help you with the reversing.

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