First off huge thanks to everyone here, the information is never ending. I’ve been meaning to start a post for awhile but I now need advice so here we go.
Here is my full build list:
I have been hesitant to start as I might have been overly ambitious and decided for my first project I’d build my own battery as well. That meant buying or building a spot welder. I opted to build the spot welder. Of all the ways I saw to make one I landed on the built by Darkkevind1978 with a slight modification.
It worked incredibly well and I got the entire battery welded up very quickly. I could apply even pressure to each point as they were independent of each other. Here is the battery so far.
I was working on connecting my e-switch and I thought I was doing everything correctly. I have a DC-DC step down converter to reduce the voltage to 12V for my switch. I spent quite awhile looking for exactly how the switch connects to the BMS and came to the conclusion it was the 2 white wires on the BMS that complete the loop for the switch. Here is the diagram for the switch I was trying to use.
After connecting everything I pressed the button and the light came on as I expected it to but I also heard a fizzing sound followed by some smoke between the BMS boards… I don’t know what I did wrong, I’m hoping I didn’t ruin the board If anyone can point out my mistake I’d be incredibly grateful.
I’m waiting for my 10AWG wire to come in the mail so I can solder on the positive and negative leads for the battery. Hopefully I’ll have the switch and BMS sorted out by then. Here are a couple more pictures of the battery that show the welds a little better.
Well I’m pretty sure the BMS is toast… I put a load on the battery and the BMS dropped to 2.4V and didn’t change regardless of the switch being open or closed … anyone have a 10S Bestech Li-Ion BMS you want to sell? lol
haha it all makes sense now!! I didn’t realize the wires couldn’t accept any power… I had read somewhere that it could handle up to 12v switch but I don’t know… live and learn. Now I just want to figure out how to get the switch to light up only when the board is on.
I would do it after the XT90 on the battery myself, that way its not completely tied in and is still removable.
What I mean is battery > xt90 female > xt90 male > buck > xt90 female > xt90 male > VESC(s). that way you can pull the buck convertor and reconnect without any reworking of the connectors. I prefer to make things modular so that repairs are faster and easier.