5000W Mini Battery Spot Welder, Portable Spot Welder Machine DIY Kit for 18650 Battery Pack Welding Tools, Adjustable Battery Welding Soldering Machine with Nickel Strip and Spot Welding Pen - Amazon.com
How to make mini spot welding using 9V batteries and capacitor - YouTube
Mini Spot Welder Machine, Portable Transistor 18650 Lithium Battery for Capacitor, Welding Tools, with Automatic Welding Mode, Single Chip Microcomputer Control and LCD Display Screen - Amazon.com