Li-po Batts Not Charging

I’m running a 10s2p set up with a 10s BMS. I followed a video tutorial on how to wire everything but something is wrong since I am not getting a charge. I apologize for the wiring that may be hard to follow.

Does the charger work?

Yeah, I’m getting 42V up until the BMS

And when measuring the voltage of the CH- and the 10th balance cable I’m also getting 42V

I have a feeling it could be a problem with my batteries that I just over discharged, or maybe with the balance cables that aren’t making a good connection but I have no clue how I would check either.

Any ideas anyone?

Tbh the wiring is very hard to follow, it would be much better If you could draw a diagram or so

I assume you bypassed the bms. Try soldering on thicker wires and see if it helps. Why do you have two switches?

It’s just one.

You have two of them. One of which is hooked up to the bms. See last pic of your first post.

I think you mean the charger port?

:joy: LOL I thought it was a second switch.

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Yeah, I figured, they look very similar.

What tutorial did you follow?

Try this, helped me find the issue with my BMS: Plug the charger in, and measure the voltage of wires that are coming out of the charger. Does the voltage show the current voltage of the pack, or the output voltage of the charger? I wired my negative wire to the ground terminal on the charge port by accident… :roll_eyes:

Balance wires should only be connected to the blalance port of the bms. You have one balance cable connected to the thick battery wire. Buy a series connector and use it to connect the batteries to the bms. Solder a thicker gauge wire from battery negative to b-.

I tried that and I am getting the full 42 volts

What do you mean use a series connector to connect the battery to the BMS? I had it rigged just like this a few weeks ago and I managed to get it to charge until I accidentally shorted out the BMS and had to get a new one. Exact same wires/setup though.