Do you really have to hand-build a spot welder to hand-build Li-ion packs? Don’t take my detour — see what you make of this one

Honestly, I haven’t figured this spot welder out — 9.9 gears, and 0.1 nickel strip only needs gear 1.5 to 1.8! I haven’t figured it out and you’re still buying it after me, unbelievable

DIY tools | A portable spot welder — niche but professional. I’ve been building a solar-lamp project lately and need to weld lithium packs for storage. I’d always used a soldering iron, but soldering lithium cells is slow and a safety risk, so I got a portable spot welder (AWithZ U3) and it works well. Compared with an iron, pulse spot welding avoids cold joints, the nickel strip sits tight, no hot iron is needed so there’s less risk of damaging the cell, and it’s very fast — one weld in 3 seconds, ideal for batch work. Spot welding was new to me, but it really is better suited to battery mods than conventional soldering