Charge and discharge problem

Hey! I started making my first board in good faith, however now I am stuck. First I connected everything together (Batteries (Samsung 30q 3000mAh 3,6v 10s2p) , BMS(36v), vesc (8V- 60v), controller and motor) and it worked! Then I plugged the charger into the battery just to check that the charger worked. The light became red and then I unplugged it since it seemed to work. Later I resoldered some connections since I had too long wires.

My problem is that I don´t understand what possibly could be wrong. The first issue is that I can´t charge the battery. I think that could be because the BMS is only rated for 36V and it is blocking the 42V charger, but that does not explain why the VESC won´t turn on. Currently I have 25.7 V coming from the battery to the VESC. Could all my problems be related to the 36V BMS, and do you think that it will work with a 42V BMS?

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Link to the bms? You should re solder the wires again. That doesn’t look safe with strings sticking out everywhere. Also your jst connector from balance wire is lot plugged in all the way

This is the one I have currently:

This is the one I am thinking to buy:

The jst connector is all the way in I think, just a poor quality BMS. I will resolder my connections :+1:

Are you sure you want to go with those cheap bms? Since you are using them both for charge / discharge… This one I been using for 3 years without any issues. It’s on the cheaper side aswell…

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I will try that :+1: thank you so much for your help.

But are you using a 42v charger on your pack?

Np. Yes 42v charger. You have 2p battery pack so try to find a charger between 1 and 2a

I already have a 2a charger :slight_smile: thanks a lot

Did/do u get a bms cutoff for full battery regen braking? I got this bms for a budget battery build I did… Only time ive ever had brakes cut out while using focbox… After I bypassed the bms and wired it for charge only the issue went away… Just curious…never had issues with my bestech

I never got a cutoff ever. But I don’t charge my battery to 42v either…

This BMS is made by SuPower ( originally but they also are sold on ebay. Very reliable, only company I trust with my batteries at the moment.

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