This topic was originally an request for custom buttery, it turned out to be DIY spot welder thread. You can view the original version of this post by opening the history.
Now back to the DIY spot welder.
I’ve designed a hardware and written the firmware for custom battery spot welder project. It’s cheap, compact and gets the job done.
Right now, I have a working prototype on breadboard ( logic part ) & perfboard ( mosfets ). I’m planning to switch to the PCB I designed soon.