Leads
The leads are made from 14 AWG solid-core wire. Originally, I used screw connectors to attach the leads. However, because they were rated for only 30 A, they heated up quickly. I replaced them with handmade copper lugs made from copper tubing.
Project story
Battery Spot Welder
A spot welder powered by a 12 V car battery and used to weld nickel strips to lithium cells.
Build timeline
Timing and control
The pulse duration determines the strength of the weld. I used a sewing machine foot-pedal case with a momentary switch and two capacitors, tuned to the pulse lengths needed to weld either one or two strips. A switch selects between them.