#Welders

No need to ask for help or use a soldering iron for battery welding; a handheld rechargeable spot welder that welds nickel strip onto batteries and stainless steel, very solid; welding power and welding time both adjustable; charges from a phone charger, really convenient to use. Screen shows 4ms, T 21℃. Comment: thumbs up for the AWithZ handheld welder, bought the H1 before, this H2 upgrades the screen and features, looks more premium and professional.

Weld cells without asking anyone for help or using a soldering iron; handheld rechargeable spot welder; welds nickel strip onto cells and stainless steel, extra solid; no welding guide needed, weld time is adjustable; charges from a phone charger; very convenient to use. Title: colour screen with adjustable weld mode and strength, handy for repairing and DIY-building packs. 1 comment: the AWithZ handheld spot welder is good, great for 18650 or 21700, keep one at home, fix your own batteries and save on repair bills.

How much is the spot welder?

Building a 21700 five-series pack with Samsung 40T cells (INR21700-40T); the welder is an AWithZ UK1, 5V (2.4A) input, 8.4V output voltage, 1380A current, Shenzhen Juequi Technology; on power-up it has adjustable mode, gear, trigger and continuous; its pen doesn’t weld the moment it touches, you also have to press a switch — he’ll show that when welding. The kit is a Dayi A3 pin-terminal one, open it, there’s nickel inside, tip it out. How the cells go: the bent part faces this way, this is the main −, so the negative goes on this side; once in, locate the main − and main +, this is positive; join the main − first, the small nickel piece goes here; unlike the previous pen that welds as soon as it touches, this one only starts when the switch is pressed, very convenient; the large nickel goes on; flip it over, weld the main + first, then put it in; this pack is now connected. Gauge: by the way the case sits, the gauge goes at the back, red to L+, black to L−; set it in; pack welded, lid on, there’s a spring that must go in or the button won’t come back up, four screws in; find an A3 tool and try it; have you learned to weld a pack now? 159 comments: where to buy brand-new genuine cells, JD / Taobao / Pinduoduo are full of fakes (3); are 5 × 4.0 reliable, EVE 40P for about ¥100 (2); how much is the welder; tabless vs Sony C6; which welder for copper shims.

Welding batteries — no need to ask anyone for help and no soldering iron; this is a handheld rechargeable spot welder that welds nickel strip onto cells, and the welds are really solid; welding power and welding time are both adjustable; a phone charger is enough to charge it, really handy to use. All comments are ‘share’.

Weld batteries yourself, no asking for help and no soldering iron; this is a handheld rechargeable spot welder that welds nickel strip onto cells and stainless steel, and it holds really well (no voice-over in the second half). Title: clear screen, simple operation, first-rate welds, a must for hardware-tool enthusiasts. All 9 comments are ‘shared’.

UF20B welding 0.3 nickel-plated — the graduation settings! 18650: 30 positive, 50 negative — tested myself, solid welds with no cold joints, double your battery-pack assembly efficiency! #SpotWelder #BatteryWelding #DIYLiIonBattery #ToolReview #GoodFinds

The comments say I can’t even figure out the AWithZ spot welder; honestly, I haven’t, I’ve tried lots of settings. Because the Jiashikai negative is steel, I test on a stainless-steel knife: for 0.1 nickel strip on this cell the gear only needs to be 1-point-something, 1.5 is enough, and there won’t be a problem; how many gears 0.15 nickel strip needs I don’t know, bumped to 2.5 to try: too high a gear blackens it, it’s already throwing sparks, the result isn’t great, probably still not dialed in; the cells are bought and on the way, I’ll keep experimenting with this AWithZ spot welder. Title: 9.9 gears, 0.1 only needs gear 1.5–1.8; “I haven’t figured it out and you’re still buying it after me, unbelievable”. 207 comments: ordered from your storefront, arrived today and won’t power on (check whether it has charge; if it doesn’t work, return it right away); my microwave-transformer welder failed too (you’re going down the road I went down; the money for a hand-build buys one of these); a Zhongwei Zhixing 30s can’t weld 0.1 nickel-plated stacked on 0.1 copper to a Jiashikai negative (0.1 copper needs a ¥400–500 class machine); fine for beginners to play with but later you’ll definitely want a capacitor unit (yep); get a UF20B; how about the Xiaoqiang.

What gear do you usually set this to

A high-current inductor, and a sudden thought — could it make a coilgun; clamp it in a vise to test; push in the projectile; the resistance is tiny so it needs a high-current source, which brought the spot welder to mind — mine peaks at 650A with an output of only 4.2V, and if it works this is an ultra-low-voltage coilgun; try it straight away, decent power, you can see the recoil; the improved version has a thicker coil and only needs a press, no sparks, push in the projectile and try, efficiency seems a bit lower because the gap is a bit big; back to the original — truly the most powerful coilgun with the least copper; see you next episode. Comments: go study engineering, hand-build god (3); only 3.7V? the instantaneous high current makes the field that pushes it (creator: spot welders are all 1S or 2S, mine is 1S); a 310V one only manages this much; bubble-tea straw as the rail, thin is the point; could a supercapacitor be the power source.

The creator ‘teaches you welders’: first a JX-D99 welder board (a toy) + welding pens, hooked to a battery, five MOSFETs underneath; it felt underpowered so he added MOSFETs at the back, and after a dozen or so welds it blew; bought another and it still didn’t feel up to it; then switched to an AWithZ welder, model UF20B, 1750A, 5000W instantaneous (nameplate: 6.0V MAX, 1750A MAX, 10.5kW MAX, 100–240V, Shenzhen Juequi Technology); test-welded two pieces of 0.1-thick nickel strip — welds very good, bright and clean. Comments: ‘so the conclusion is you bought a welder for a few hundred bucks’, ‘you’re teaching us to buy a welder’, ‘talked into buying yet another one’; someone says Xiaoqiang’s can reach 2500+; someone claims a 5-MOSFET board with a 4S 120C battery at gear 75 can weld 0.1 nickel stacked on 0.5 copper (creator: no way).

Unboxing the AWithZ U3 spot welder, a common tool for RC car folks: looks like a power bank, two gold-plated sockets for the welding pens, USB output doubles as a power bank, Type-C charging, 11000mAh 3.7V, ‘pioneer of small portable spot welders’; the manual matters (welding method, settings tutorial, weldable nickel / copper thicknesses); the accessory bag has two welding pens, a USB cable and a small pack of nickel strip. Use: DIY 18650/21700 series / parallel. Example, Lao Gao’s radio (Hello Radio V14) 18650 battery: before the welder he used a cell box + XT30 soldered to main + / −, charging through the balance plug was too slow, so parallel-connect an XT30 + XT60-to-XT30 to a charger for fast charge; with a spot welder no cell box is needed. Series / parallel joins on the 18650’s end metal with solder are very hard, and the heat easily damages the cell internals, so get a small spot welder, a hundred-odd yuan, two quick pops. Method: fix the cell, cut strip to length, round off sharp corners (to avoid piercing the heat-shrink); long-press to power on, push the pen pins in firmly; manual mode (press the switch on the pen, pop, welded; auto fires when the two pens touch); preheat 2 milliseconds, interval 2 milliseconds; gear turned down from 65 to 5 is enough; multi-pulse once; one pen presses while the other welds, two spots at gear 5 are already solid, four spots per 18650 (two presses) is very secure; tack the other cell’s positive, + and − joined. One 18650 is 3.7V, multimeter on DC reads 8.06V total, proving the series join. Main + and − on the front also get nickel strip: solder won’t take, the positive is an aluminium plate with a dense oxide layer that won’t tin, the negative can be soldered; once the aluminium is ‘converted’ to nickel it tins easily (comment: just file it and it’ll solder → ‘if it blows up from filing, go find him’). Balance leads to the middle strip between the two cells and to both ends; 2S done; fish paper works for insulation, Lao Gao wraps both ends in EVA foam then shrinks the film; bus reads 8-point-something volts, balance port 4.048/4.039V, normal. FPV pilots like fast charging, so the XT30 goes to an RC plane / car charger. A spot welder is a must for 18650 DIY, don’t go dumbly soldering 18650s with a big iron, too hot and risky. Comments: can you talk slower (no, 1.5× speed); soldering the voltage feedback on would be handier; where does the middle of the three 2S balance wires go; so easy, the iron always shorted before; bought a welder, time to hand-build an EV.