The customer's old case is only 130×370, so I measured three times before I dared to cut anything. 13S6P, 0.2 nickel-plated strip, UF20B at gear 38 — watching the welds light up one by one is seriously addictive. Halfway through, the welding pens touched and blew a hole right through one cell. Swapped it out and started over — newbies, remember this: position first, then press. Don't rush. BMS goes in tomorrow, it goes back to the customer the day after. Will report back.

Help: the area around the weld turns black, with a ring of burn marks too. Is the gear too high, or was the nickel strip not pressed flat? 0.15 nickel-plated on the H1, I'm using gear 45. It tears off when I give it a pull, so I don't feel good about putting it in a pack. Could any old hands point me in the right direction? Thanks!

54 × 18650, 3S18P, 12.6V 36Ah. The inverter does 600W continuous, 1200W peak. The moment I plugged in the rice cooker my heart was racing — rock solid! Welded with the P60F, double-layer nickel strip in one pass, not a single cold weld. It took two evenings; the hardest part wasn't the welding, it was cramming this pile of modules into the storage box and still leaving room for airflow. The video shows the whole process. If you want to build one, follow along, and ask questions in the comments.

I was always too scared to touch spot welding — afraid something would blow up. The day my U3 Pro arrived I practiced on scrap nickel strip all afternoon, and today I did it for real. Six salvaged cells, sorted by internal resistance. Tested it with a flashlight after welding: in 38 minutes it charged my phone full twice. Grinning like I'd found money on the street. My wife says I'm acting like a kid. Yep.

Color screen, dual pulse, gears 1–99, welds up to 0.25mm nickel-plated strip. This generation switches to new grade-A cells, with 40% more battery life than the last one. If yours has arrived, snap a photo of it on your desk, tag @AWithZ Official and add #MyH2 — we'll pick 10 people to get a 5-meter roll of nickel-plated strip.

You only find out how many pitfalls there are once you build your own FPV drone packs: the negative side of tabless 21700s is really current-hungry — I had to push the UF20B to gear 52 to get full penetration. Paired it with a 40A BMS and measured every cell's internal resistance before welding; max spread 2mΩ. Flew three packs, and the shell wasn't hot when I touched it after landing. Happy. The recipe is attached to the project. Judges, please go easy on me.

How should I set it for 0.2 copper stacked with 0.12 nickel? My UF20B is at gear 80 and it still won't hold — not a single mark on the copper side. Do I need to add flux first?

Click the knob, press the tip, and you're welding. For house calls fixing shavers and electric toothbrushes I used to haul a big bag; now it's just a UK1 and a roll of nickel strip and I'm out the door. Still got a little thrill from the unboxing — the box is really nicely made. 0.15 nickel-plated is easy; 0.2 needs gear 70 or higher. The downside, to be fair: the battery is built in, so after a lot of welds you have to stop and let it recharge.

Three 18650s plus an e-bike headlight, with a water pipe for the housing. Welded the nickel strip with the H1 — tiny little thing, handles 0.12 strip with zero effort. Switched it on outside at night and the neighbors thought someone had left their car headlights on. Hahahaha. Pic 2 shows the internal wiring, for anyone who wants to copy my homework.

The next Parameters table will be prioritized by vote count. After voting, tell us in the comments which combo you'd most like to see (material × thickness).

The wires in v1 were too thin and got hot, so this time I went with 2S 21700 plus a 30A BMS, and double-layer nickel strip. This machine is seriously small — it sits in a corner of the bench without taking up space, recharges in a few seconds, and I welded 40 spots in a row without ever having to wait. Best part when it was done: not a single spot needed re-welding.

Maybe a dumb question: when welding nickel strip on the negative side of a cell, do you need to go two gears higher than on the positive side? I see the pros setting it that way in videos, but nobody says why.