AWithZ portable Li-ion spot welder — building a power-tool battery pack with the AWithZ portable welder

The Village’s Only Primary-Schooler builds a Dayi-style 20V 10-cell tool battery with the UK1 (Samsung 2800mAh, genuine imports, matched internal resistance / capacity / voltage): manual gear 98, one pulse and it’s solid, ‘can’t pull it off’, better than his old small handheld; tried auto mode, not to his taste; two-pulse rapid-fire at gear 95 is better, turned down later; tape on, BMS fitted, done; the UK1 is compact, welds ordinary cells, not large prismatic cells; gold-plated plug, optional foot switch, button on the handle, Type-C, replaceable pins; pinned: 0.15 nickel-plated strip, set mid-range; blackening — turn down, won’t stick — turn up

His home-made microwave-transformer welder is too bulky to carry, so he got the AWithZ portable welder to see how it does. Found a Dayi-style tool battery (2-98V 20000, 10 cells); Samsung 2800mAh cells, genuine imports, each with a stamp on the negative end; internal resistance, capacity and voltage were checked before and match, so straight in. No dedicated nickel strip, so use the 15-cell one and trim the excess. Hold the power button two seconds, manual mode, gear 98, one pulse; first time using it, unfamiliar; quite solid, can’t pull it off, fully meets the requirement; keep going, never expected something this small to be so effortless, nailed it; pretty solid; an earlier small handheld was a bit lacking on this strip, never expected this one to handle it completely; supposedly max current 1200A, whether it’s really that high doesn’t matter, if it welds well that’s OK. Try the other mode (rapid-fire): two pulses, OK; gear set to 95 to try; it’s back in manual now, auto mode isn’t to his taste, sometimes it fires before he’s finished positioning; though auto mode has an adjustable wait time; still prefers manual; two pulses like this is better; turn the gear down a bit. Done, checked for misses; assemble: tape along both sides on top, BMS on and welded, finished; try it (angle grinder). The welder again: compact and easy to carry, didn’t expect much, just wanted portability, but the results are good, welds ordinary cells, definitely not large prismatic cells; the pen plug comes out and fits tight, gold-plated; the foot switch plugs in here, not normally used, just the button on the handle; charging cable, Type-C port; pins are replaceable, pull them out with pliers; nice design. Comments (23): how to set the two modes → by nickel-strip thickness, no blackening and it sticks is fine, 0.15 nickel-plated set mid-range; too pricey (1) → make one from a microwave transformer, works just as well but took two days; brand-name gear looks classy and welds well, AWithZ knows how to make a product (1); 98 is too high / will blow through; why is so much of the negative-end wrap missing; can it weld Jiashikai; can batteries be shipped yet.

Outcome

Steps9 steps · click a frame to jump

1. 
   1. The home-made microwave-transformer welder is too bulky; got a portable UK1

   His home-made microwave-transformer spot welder is too bulky to carry; now he has the AWithZ portable spot welder, let’s see how it does.

   00:00 – 00:13
2. 
   2. Dayi-style 20V 10-cell; Samsung 2800mAh genuine imports, stamped negatives; matched resistance, capacity, voltage

   Found a Dayi-style tool battery (2-98V 20000, 10 cells); Samsung 2800mAh cells, genuine imports; each negative end stamped; internal resistance, capacity and voltage checked earlier and matched; straight in.

   00:13 – 00:40
3. 
   3. Borrow the 15-cell nickel strip and trim it; hold power 2s, manual mode, gear 98

   No dedicated nickel strip, so use the 15-cell Dayi one and trim the excess at the back; start welding; hold the power button two seconds; set mode to manual; gear 98; one pulse.

   00:40 – 01:07
4. 
   4. First use: one pulse and it’s solid, can’t pull it off, fully up to standard; weld them all, effortless

   First time using it, unfamiliar, so one pulse and hold still; quite solid, can’t pull it off, fully meets the requirement; keep going; never expected something this small to be so effortless, nailed it.

   01:07 – 02:05
5. 
   5. Better than the old small handheld (which was lacking on this strip); claimed max 1200A, if it welds that’s OK

   An earlier small handheld was a bit lacking on this nickel strip, never expected this one to be fully up to it; supposedly max current 1200A, whether it really is doesn’t matter, if it welds well that’s OK.

   02:05 – 02:40
6. 
   6. Try two-pulse rapid-fire; gear 95; auto mode not to his taste (fires early), wait time adjustable; back to manual, turn the gear down

   Try the other way: two pulses, OK; gear set to 95 to try; now back in manual, auto isn’t to his taste, it starts firing while he’s still positioning; auto has an adjustable wait time; still prefers manual; two pulses like this is better; turn the gear down a bit.

   02:40 – 03:33
7. 
   7. Done, no misses; tape both sides; BMS on and welded; fitted and tested

   Finished, checked, no missed welds; assemble: tape along both sides on top first; BMS on and welded, done; try it.

   03:33 – 04:02
8. 
   8. UK1 is compact and portable, results beyond expectations: welds ordinary cells, not large prismatic; gold-plated plug

   Compact and easy to carry; didn’t expect much, just wanted portability, but the results are good; welds ordinary cells, definitely can’t do large prismatic cells; the pen plug comes out and fits tight, gold-plated.

   04:07 – 04:35
9. 
   9. Foot-switch port (not normally used, handle button); Type-C charging; replaceable pins

   The foot switch plugs in here, not normally used, not his habit, just the button on the handle; charging cable, Type-C charging port; pins are replaceable, pull them out with pliers; nice design.

   04:35 – 05:16

Bill of materials

Creator’s tips

• Set the UK1 gear by nickel-strip thickness: no blackening and it sticks is right; blackening — turn down, won’t stick — turn up; 0.15 nickel-plated, set mid-range (pinned)
• Beginners are steadier in manual mode; auto mode can fire before you’ve positioned; the auto wait time is adjustable 02:57
• Check internal resistance / capacity / voltage match before building the pack 00:34
• Hold the power button 2s to switch on 00:54

Pitfalls

• Comments: gear 98 is too high / will blow through
• Can’t weld large prismatic cells 04:20
• Comments: too pricey

Li-ion safety

Quotes

Cost & time