A must for battery welding: a solid weld in 1 second, plus how to stack the sale discounts

UF20B unboxing, up close: 18 × 8 × 9.5 cm, dual supercapacitor 6V / 1750A, welds 0.4 nickel-plated (with flux), 8mm universal pen sockets + foot-pedal / one-piece-pen trigger port, 1.5mm alumina-copper pins

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.

Outcome

Steps5 steps · click a frame to jump

1. 
   1. Brand take and buying decision

   Among small welders AWithZ is one of the better consumer-grade brands — solid quality, looks and features, somewhat pricier than DM; he bought the shop’s value model, the UF20B, on the 618 sale discounts.

   00:00 – 00:25
2. 
   2. Accessories, dimensions and ports

   Unit, 220V power cord, a pair of welding pens, a small roll of nickel-plated steel strip, sandpaper; 18 long, 8 wide, 9.5 cm tall; front: display, two function keys, two 8mm welding-pen sockets; the small hole 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.

   00:25 – 00:53
3. 
   3. Cooling design: fan, bottom-edge notch, L-shaped plug

   Rear vent grille and a built-in fan cool the MOSFETs, capacitors and power supply; a notch along the bottom edge of the case plus an L-shaped power plug on the side keep airflow when it’s stood upright; the designers put thought into it.

   00:53 – 01:09
4. 
   4. Specs: dual supercapacitor 6V, 1750A, 0.4 nickel-plated (with flux); 1.5mm pins

   A dual-supercapacitor 6V machine with a 1750A peak; it welds 0.4mm nickel-plated steel strip but needs flux; after plugging in, let the capacitors charge for a moment — it’s fast; the pins are 1.5mm alumina copper and work for 0.2mm nickel strip.

   01:09 – 01:35
5. 
   5. Test welds: nickel strip holds, stainless works too; verdict

   The sockets take universal 8mm rubber plugs; plug in the pens and the test welds are very firm, stainless steel is fine too; a spot welder is a must for lithium pack building, choosing a good one matters, and this one is good.

   01:35 – 01:58

Bill of materials

Measured on camera

Creator’s tips

• Welding 0.4mm nickel-plated steel strip needs flux 01:16
• After plugging in, let the capacitors charge for a moment before welding (it’s quick) 01:24
• The trigger port can take a foot switch or a one-piece welding pen 00:49

Li-ion safety

Quotes