Spot Welding with Supercapacitors
Using the Kekk supercapacitor spot welder to weld nickel-plated steel strip to 18650 lithium-ion battery cells.
Kekk Supercapacitor spot welder:
https://www.aliexpress.com/item/1005005041354620.html
SEPIC buck-boost power supply:
https://www.aliexpress.com/item/1005001278107340.html