Help! Where do I attach the negative charging cable


I can’t seem to find the c- terminal

That question can be answered by a wiring schematic of your bms.

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I bought the battery online but they didn’t add the charging cable to the BMS…

Yeah again, find a wiring diagram of your bms. Get on Google, search the type of bms you have and find a wiring diagram showing where everything connects. Its not that hard and you’ll have an answer before anyone responds here.

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But I don’t know the brand. And I don’t want to take any risks since it is glued to the battery itself :confused:

Where did you get the battery

Bought it on Alibaba

‎ link?

Problem is I had it costumized

BMS should have a brand or model.number on it somewhere try to find it and then Google.

generally P- is charge / load negative, B- battery negative. i bet you’ll see the markings on the PCB if you take cover off…

but it’s hard to tell what’s happening with yours so please find a schematic first.


^^ this. Look for a p- or a c- , both usually work.


Thank you guys :smiley:

So I wrote to thw guy I bought the battery from and he tells me that I should attach the negative charge port wire to this wire. I find it strange since it is the main negative lead. Screenshot_20181211-081034 IMG_20181211_081106

And if so where do I attach the red charging cable?

Your BMS uses low side sswitching so all high side wires are common. I.E. all positive voltage are connected together.

^^^ This

Basically the red wires don’t go to the bms. The positive charge port goes straight to the battery

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