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 John Hickey

I wanted to build a spot welder for making 18650 batteries, but then I saw this and decided to give it a try. I don't know the nickel strips that came with it. I used this one and it worked great - https://www.amazon.com/gp/product/B07TM9XHNX/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 The welder was very easy to use. I just turned it on, turned the power all the way on and in a matter of minutes I made 3 battery packs of 6 cells each. I had 0 defective welds. ZERO! It has worked with a good weld every time. I have never tried lower power levels. This only worked on max. Maximum power ensured a good weld with no burrs and deformation. If I were you I would just start with it. I've welded 18 batteries, top and bottom, so 36 welds, and I still have about 90% of the energy left in the bank. I had some concerns about how long the tips would last on the sensors, but they seem pretty sturdy. The probe wires are a bit short in my opinion, but not critical.