#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.

This thing must cost a thousand-plus!

Tell us about the battery life

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).

A music-only video, everything in captions: gather the parts; lay out the cells in 2P14S (spot weld the nickel strip); connect the sense wires; cut a wiring port in the case lid; mark the wire order (each sense wire); cut the charge / discharge port and fit an XT90; before plugging in the harness, measure again with a multimeter to confirm the soldered wire order, rising step by step; measure the output voltage, charge to wake it if there is none; smear structural adhesive over the case openings for waterproofing; finished label 14S 24Ah 120A BMS. 102 comments: every pack needs a BMS, right; how much to make one; would a BYD 3.2 cell at ¥20 each work; wouldn’t big CATL prismatic cells be better; the nickel strip can’t carry the current; ‘hand-built with an AWithZ UF20B’.

A sudden idea: lots of lamps to wire up, and buying a connector every time adds up, so can the spot welder weld nickel strip straight onto the lamp (the bulb’s metal base), bent into an arc as a wire terminal? Try it: one shot and it’s on, very solid — he yanked the cap on the bottom clean off and the weld didn’t let go; on the side it sticks with one shot; a bit hard to hold down, need something to brace it; one spot wasn’t pressed tight and simply got burned through — which shows it can weld thicker than this, not just this thin; the current setting is on the strong side, for thin stuff turn it down, and at a really strong setting it could probably weld a stainless-steel frame, next episode; the spot welder is great fun and can be turned to all sorts of uses; a bit of tape for insulation and you can make a lamp that hangs from the ceiling, extremely sturdy. Comments: it works but for safety a lamp holder is more reliable, safety first, convenience second (4); asking for trouble, relying on insulation tape?; you’re not an electrician, is this just an ad; which model; if both tips touch your hand at once do you get a shock; I have the top-spec one too.

The solar-lamp project needs lithium packs welded; a soldering iron is slow on lithium cells and a safety risk, so he bought an AWithZ U3 welder, the Li-ion version with 11000mAh (on-screen specs: 0.1mm copper, 0.35mm nickel-plated, 0.35mm steel, 0.2mm pure nickel) — not expensive, good enough is good enough; if you have more use cases, buy a more professional model. Looks: palm-sized; welding-pen socket top-left; 2-inch colour screen in the middle; two buttons on the right (adjust key, power / option toggle key); USB and C ports on top — the official notes say besides charging it can emergency-charge a phone, but inefficiently; manual weld key on the right (touch to trigger in manual mode). Long-press to power on into the main menu: battery and temperature in the centre, 6 sub-menus toggled by tapping, short-press the adjust key to change values; settings menu top-right (language, pulse interval, sound etc.), defaults are fine — the only thing to set is the gear: 80 fine gears from 1.0 to 9.0, matched to the material, neither too high nor too low. The pens use thick copper wire — low resistance, low loss, no heating; detachable alumina-copper welding pins are safe and durable; the handle has a manual weld key; the pens are 40 cm long with a front-facing opening to maximise usable length; line up with the socket and push in. Set the parameters before use: auto mode, 0.5s trigger, 2 pulses, gear starting at 3; test on a dead CR2032 coin cell with the material supplied by the manufacturer: hold one pen still, press the other down close by, the machine welds automatically with a ‘beep’; check the weld by prying with pliers to see how solid it is, and if the weld is weak, raise the gear until it’s perfect. Verdict: highly recommended for DIY battery or small-appliance welding. Comments: what price, where to buy, how to remove a welded joint without damage (creator: ¥100-odd; needle-nose pliers will get it off but leave marks); ‘I have this one too, ¥200-odd’.

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.

The creator normally uses a DIY spot welder that has to be charged up before every use, which is a hassle; a follower said his own DIY build was expensive and fiddly and asked whether there is a good-value spot welder. The star of the unboxing: the AWithZ handheld color-screen spot welder. Peel off the protective film; a second small box holds nickel strip, a nice touch. The manual notes: make sure the pins have cooled before changing or removing them to avoid burns, the weld effect weakens below 25% battery, thermal protection, long-press for quick adjustment, manual spot welding. The interface is friendly and easy to pick up; the settings menu covers language, weld sound, screen brightness, screen flip, auto power-off and factory reset; the whole unit is light and compact and feels okay in the hand. A quick spot-weld test first — it holds reasonably well; dial in a suitable gear and weld the pack directly; the pack is finished before the DIY welder has even finished charging. Verdict: more convenient than the DIY unit; for simple 18650 packs a handheld like this AWithZ is worth considering — good value, portable, ready to use on power-up. Comments: some think the capacitor type is a better fit (the creator liked that), asked the max thickness it can weld (liked), runtime, gear, whether 21700 can be welded (creator: yes); one said the welds look a bit black.

Creator TOP speaks to FPV pilots: field battery boxes, long-range packs and radio batteries are all built from cells, and he has already posted a welding tutorial, an internal-resistance test method, wiring diagrams and an open-source battery-box shell. The key piece of kit is a spot welder; this time he upgrades to the AWithZ UF20B and unboxes it while explaining how to use it. First he shows that a soldering iron struggles to tin a cell terminal, gives cold joints, and long heating is a safety risk, while the spot welder fixes it solid with a few small sparks. Nameplate: max output voltage 6V, max current 1750A, power 10.5kW. Feature-wise he likes the switchable trigger mode: in auto the weld fires as soon as the pen tips press down, in manual you can position first and then press the button to fire, which feels more assured; there are plenty of parameters (trigger time, multi-pulse) but he basically only uses the gear. Too high a gear burns through the strip, too low won’t hold; with 0.15mm nickel-plated steel strip folded double as the example: gear 1 is too shallow and pulls apart with one tug, gear 4 won’t pull apart but is shallow, gear 6 welds through to the back, gear 7 is thoroughly perfect — for 0.15, remember gear 7; gear 99 is for thicker material, up to 0.4mm. The settings menu has a page-by-page ‘experience sharing’ tutorial that is beginner-friendly. Closing: battery-shop bosses drive Ferraris, play with quads and never run short of pocket money, link in the showcase.

The creator picks up an AWithZ UF20B (AWithZ focuses on spot welders; a must-have for repair / DIY): main unit, manual, power cord, welding pen and a free roll of nickel strip. Neat finish, cooling fan at the rear, a slot on the base so it also cools when stood upright; max output current 1750A, officially rated for 0.15mm copper strip and 0.4mm nickel strip. On power-up the screen shows the AWithZ logo and the internal supercapacitor charges first, done in moments; long-press to power on, short-press the power key to switch settings; the trigger port takes a foot switch, set to foot-pedal mode. The default gear 05 is on the low side, max is 100; after welding nickel strip the welds are bright as new with no blackening, and pulling on the strip tears the strip while the welds hold tight. Key point: a higher gear is not a stronger weld — too high burns through and wrecks the strip and the weld is actually weaker; like a soldering iron’s temperature, right is right. Commenters ask for a ‘gear vs nickel strip thickness chart’.

Unboxing a ¥100-class mini handheld spot welder: in the box are the welding pen, a charging cable, a sheet of sandpaper and a pack of nickel strip. The body has 11 gears, a manual / auto indicator and a battery indicator; long-press to power on, button to change gear, long-press to switch mode; Type-C charging, arrived fully charged. Tested on an 18650 and a coin cell (which a soldering iron basically can’t solder): gear 8 auto mode, two welds first, then six, pulled and torn and they won’t come off — the strip tears instead; welds on the coin cell are round and solid. Verdict: for the modest volume of home use, worth recommending. In the comments the creator replies the strip thickness it can weld is 0.2; a top comment questions the built-in battery’s lifespan, saying a supercapacitor model would be better.