Review on SUNKKO 737G+ Battery Spot Welder, Pulse Welding Machine for Lithium Battery Pack, Compatible with 18650 and 14500 Batteries, Works with 0.35mm Nickel Strips, 110V by Rich Ferguson

I have spot welded several batteries (less than 50) so far. I wish I could give 4-1/2 stars. The strips included in the kit did not have an acceptable weld even when using the highest settings. At the moment I don't know if the supplied strips are a problem or if the welder isn't getting enough power for the supplied strips. I checked (with a micrometer) the thickness of the strips to see what I was actually working with. The supplied strips are 0.142 mm thick. The 0.14 mm thick strips were welded at the highest setting of the welding machine, but the weld seam broke when the voltage was applied. Any weld that breaks or fails before the parent material is unacceptable under any standard. Unhappy with the result of the 0.14mm strips I went to my collection of nickel strips I had on hand and found some 0.110mm strips. I reset the settings on the welder where I could start "experimenting" and with the 0.11mm strips I started getting good welds (IMHO). The next step was to reinforce the welds. I was very happy with the results as the strips (original material) came loose and the weld held tight. I made a few more adjustments to the welder settings and ended up being a very happy camper with a new toy (oops! - a new TOOL) for battery assembly and other projects.