Review on 🔌 Portable Spot Welder Machine, Kerpu Mini Spot Welder with Energy Storage 5000mAh for DIY 18650 Battery, Spot Welding Equipment. Type-C Port 2A Input, Portable Battery Welder. by Eric Froedge

Contained nickel could not be fully welded to itself at full power; Welds burst with very minimal metal deformation and no breaks. The material included is 0.1mm thick, making it easy to weld. Another review claims that the nickel is not pure but plated iron, which is also problematic but could explain some welding difficulties. The kit gets the job done (barely) and is more comprehensive than the $16 kits that require circuit modification for reliability and a separate battery. It's probably better to use the funds to spend $150 on a real low-end spot welder. Leave the lights on while you work. I built a 13 cell pack and the probes got relatively hot and 3 welds per contact at a beginner's pace. This work (and 20 test welds) also reduced the load from the 4/5 it came with to 1/5 the load.