#Hands-on skills

Opens with a burnt hand by accident; looking at the delivery-order numbers these days, no more grind — home for National Day, with gear: multimeter, AWithZ spot welder, the ‘fake’ cells bought online (a joke), a small soldering iron, solder wire, the bought cells, nickel strip; also found a power bank at home (3.7V 10,000mAh) and opened it — of the five cells, three are different and not connected together, two are connected; turns out those three are fake Li-ion cells, ‘fake Li-ion cells have such a long history’; measured no voltage on the three, removed them with the iron; red +, black −; the good ones and the new cells go in parallel and back in; nickel-strip leftovers, only this tape at home for insulation. At the key moment out comes the AWithZ spot welder, because it’s small and light — bringing the big welder home would be too heavy and a hassle; screen shows gear 3.2, ‘set it to about 5’; 0.15 nickel-plated steel strip is a lot thicker, a layer of 0.1 stacked on top; welded, + and − soldered with the iron; (BGM) hand straight-up burnt with a blister; power bank assembled, charge the phone as a test before fitting the shell; shell glued on. Comments: the pulse is too long, it’s arcing (so that’s it, thanks); get an internal-resistance tester and match cells, it’ll last longer (coming later); a nickel-strip short did it (stay safe); can it still be saved (isn’t that what you’re doing); put those two in as well (they’ve been around too long, no good).

Another manufacturer sent a product to test: the AWithZ small handheld spot welder H1; AWithZ is a company that specializes in spot welders; compact, suits DIY, not expensive, worth buying if you weld only occasionally. Long-press the side button to power on; short-press the top button to change gear, 11 gears in all; long-press to switch between auto and manual. The 0.1 nickel strip that came in the box: at gear 1, one manual tap feels smooth, but a tug pulls it off by hand (the strip tears a little); at gear 5 with three more taps it can’t be pulled off by hand, and pliers tear it apart. 0.2 thick nickel strip: comes off with a light tug at gear 5, and at the top gear 11 comes off with a bit of force — 0.2 isn’t really doable. 0.15 nickel strip welded onto a cell at gear 11 can’t be pulled off by hand, pliers needed, quite solid; 0.1/0.15/0.2 all tried, the thickest it can weld is 0.15. The ¥40–50 welding board he bought before needs a high-discharge battery; the battery he built himself (doubles as a power bank / car jump starter) cost ¥100-odd, so ¥200-plus for the set, and it breaks easily — this is the third one; had he known AWithZ made these he wouldn’t have bought that; the H1 suits hobby DIY, but if you weld a lot and hard, don’t expect ¥100-odd to meet your needs. Comments: the free one is great, the one you buy isn’t (7); low needs, a few small packs now and then, just right; the battery type has too little current, you still need a capacitor (creator: this one only sells for ¥100-odd); officially rated for 0.25 (there’s fine print); only two MOSFETs on the board, no good; 0.15 won’t weld at all, only 0.1; this thing is no good, I bought one (creator: mine was free).