The creator rates AWithZ as one of the better consumer-grade welder brands — solid build, looks and features, a bit pricier than DM; he picked up the shop’s value model, the UF20B, on the 618 sale discounts. In the box: the unit, a 220V power cord, a pair of welding pens, a small roll of nickel-plated steel strip and a sheet of sandpaper. The unit is 18 cm long, 8 cm wide, 9.5 cm tall; the front has a display, two function keys and two 8mm welding-pen sockets (universal 8mm rubber plugs). The small socket next to the negative port is the manual trigger for the supplied pens; the universal trigger port on the right takes a foot switch or a one-piece welding pen. The back has a vent grille with a built-in fan cooling the MOSFETs, capacitors and power supply; a notch along the bottom edge plus an L-shaped power plug on the side mean it still gets airflow when stood upright. It’s a dual-supercapacitor 6V machine with a 1750A peak; it can weld 0.4mm nickel-plated steel strip but needs flux for that. After plugging in, give the capacitors a moment to charge — it’s quick. The pins are 1.5mm alumina copper, suited to 0.2mm nickel strip. Test welds on nickel strip held very firmly, and stainless steel was no problem either. Conclusion: a spot welder is a must for building lithium packs, and this one is a good choice.