Boss level custom spot welder

This is my pack that I just welded up using this DIY Tab welder…

I modified my design slightly because the wires were overheating… There’s now a short length of semi-rigid 16mm² cable from each terminal of the battery going to an electrical connector with to 2.5mm copper electrodes coming from each terminal.

New cable…

Tried using nails for electrodes… they just melted!

Design as it stands…

Some welds…


I did an in depth test of the spot welder in order to determine the perfect time flux.

The multi-stage feature is amazing, it melts the nickel beyond 2x and has 6x available. I am sure it’s 0.3 capable or even suitable for other metals. Enjoy


Ordered one…now show us where to get a cheap foot pedal and hand welder!

The pen is included. Any no nc pedal at ebay works. 3-10 usd will do.

It’s easy to do. There’s 3 wires com,normally open and normally closed. You need to solder com and normally closed to a dupont wire,insulate the third and you are done. Dunno why the sellers send a tiny wire, I had to add an extension.

also the diagram was incorrect. white,red and black were actually yellow,red and green…and red was not the supposed red. After a few combinations i figured it out. I did a few welds and is quite comfortable.

This is my pedal.

welding pen is included as well as soldering pen in ‘full kit’? In that case I am sorted :slight_smile: thanks

Exactly. The pen you can see in my videos and the hakko solder iron

Left the pen provided by Aulakiria and right another made by me. It is easy to do. Two 50 cm 8awg wires 2 pure copper pins and some shrink pvc. I did it because I am currently testing copper weld and I am making some serious pressure, i don’t want the pins to bend.Aulakiria’s is way more comfortable than mine.

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Will this work with a 4s LiPo or is 3s a must?

Yes works with 4s but it is more dangerous. You must go easy and set lower flux times if you use 4s. That’s why aulakiria recommends 3s. I guess installing heatsinks and fans are also a must if you use 4s.

I promised myself I wasn’t going to spend any money today…dammit

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I did a small video testing copper

this needs more testing, The copper takes a slight damage on the surface because is too thin to work with. The contact must be perfect or the short makes holes.

copper is almost 5 times more conductive than pure nickel while disipates better the heat so it’s worth testing. 0.1 almost equals 0.5 nickel strips. I will test some thicker strips next week. let’s see…


I succeeded making a battery with pure copper. I did a video showing the proccess. works like a charm.

In case you wanna use copper make sure you understand this: You need 4s lipo, that makes the boss welder more dangerous. Copper is difficult to work with, Do not try this if you are a rookie battery builder. The contact must be perfect or it will make a short and damage the copper strip and probably the cell. Use manual mode only. Automatic is very dangerous. Wearing gloves and glasses is MANDATORY. Lots of sparks and projectiles. Enjoy the video


i got mine earlier this month. It is awesome. And the dude that sells it is awesome too. Usually gets back to me in a day (probably because of time difference). I hope this guy makes a killing on these as he deserves to. I’m very satisfied with it.

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where do you source the .1mm copper strip?

Very cool! If the .15mm nickel = about 15A capacity per strip (so we use layers) - how does this compare?

I have 4s in plenty - easier for me to find than old 3s…

Thx for the video - liked the music too!


This is just amazing :slight_smile: Can you weld copper with the provided spot pen or how does your modded one differ?

Yes, He is a genius yet a humble and polite man. I can tell this right now: Aulakiria will be legend in the spot welding world !!

2 Likes i got mine there. The music is “fali faly” by kepa junquera. He sings in a spanish old tongue (Basque)

I did it with aulakiria’s. I realized it’s not just pressure what it needs but perfect contact. I still need to do more testing with the copper. Copper vs blade= perfect Copper vs 18650= perfect Copper vs copper= weak…extremely weak. Not viable. Therefore i asume it’s better doing the parallel with nickel (very low conductivity needed) and the series with copper (Very high conductivity needed). Also i got permission today from aulakiria to test with more voltage (even more danger aaaaaaaah) Maybe increasing the voltage copper vs copper makes decent welds… but i do not find it neccesary. Copper is extremely expensive and the parallel made with copper would be a waste. I’ll test more thickness in a few days. I’ll let you guys know the aftermath.

Anyone bought this in the US? If so, what is the amount of customs declaration?