BMS set up correct, but won’t charge through the BMS

Set up my BMS just like I did on my last pack and it won’t charge through it. It will charge when I bypass the bms all together. I checked and all of my leads are connected in the correct order, test by voltage of each one. The BMS is getting very warm once I plug it in as well. I also tried three different BMS’s so I don’t think it is a problem with a single bad Bms.


Any ideas?

Wrong balance cables. Check if you go from cell 1 to plug 1, cell 2 to plug 2. Etc. If it is not correct you’re balance board off the BMS will be become hot and maybe start smoking.

Just to clarify, plug 1 goes to the cell 1 positive terminal (the same spot as the positive lead for the whole battery) and then each addiction plug goes to each matching cell number positive terminal too?

Yes Maybe you soldered the wires in reverse. Check if the black wire of the balance connector goes to B1+ and the red wire to B10+ of your battery. As @pjotr47 mentioned if you mix up balance wires the BMS gets hot (smoke).

I checked this and had someone else double check. It is good. Any other ideas? This is why I am so stumped.

Ok, so I think my BMS the B1+ goes on the positive of the cell that is the negative for the actual battery. (So yes reversed, you were right) but then I switched it to be wired correct and it’s still not working. Would how I had it before break the BMS?

if you miss one balance lead usually you kill the bms

did you fix it?

move the charge wire on bms to the P- hole, that is your charge and power out.