This is a write up on an early but working design for a CD Spot Welder. Its fet switched and electrically isolated with intent of actually being able to control all electric fab processes. The weld energy comes from a bank of Maxwell super capacitors.
I needed a large quality lithium ion pack. Part of that is high quality cells properly joined (a bms being the other liability/safety component). China cells or packs featuring cells with fire right in the name seemed like too much truth in advertising and american made either comes with limitations like requiring complicated battery auth with bms or $. So I decided on assemble your own from sourced cells. This isnt meant to be a post on pack construction though. I will probably publish one at some point because a lot of the YouTube community and especially ebike community scares me speechless when it comes to litium ion pack construction.