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Boss level custom spot welder


Depends… nickel does not make the machine sweat. I guess you can finish an entire 12s4p pack with 5000 mah with just one charge. If you keep the temperature low there’s no need to stop.
Copper is different. The performance is better at full charge so I reloaded my lipos twice. Besides this was a kinda big thing 132 cells. The pen literally burns your fingers so you need to stop every few welds. Maybe it is not noticeable at the video but I used 3 different pens.
I was swapping them every 4 welds to go faster. My machine never reached high temperature with the cooling mod I did. Most of the time was under 40 celsius and barely a few times reached 41 but never above that. As long as you keep the fets under 50 celsius things go smooth. Of course fets are not eternal. Sooner or later they will blow but not sooner than expected if the temperature is under control.
I will say again that this Wonderful machine was not designed for copper and I do not recommend it. Capable? Hell yeah. Recommended? No. Besides 0.15 nickel strips should suffice for most sk8 packs.
This was an ebike pack and copper was the best of the best. It is a totally Insane battery. I even think I overdid it. Is way more powerful than intended.


I am a ruthless mf. I will sing myself “despacito” in all my videos hence forth.
Mwahahaha :joy:


Thanks for the detailed reply. Yeh i didnt see how you switch pens… though I did think whenever it would feel nice to hold the pen such close to the tip… as others I think use long prongs (at least for a lot of sunkko welders, for example)


The pen is really comfortable. Welding nickel the heat is not so noticeable.
Aulakiria has a video making tons of welds without gloves, no problem at all.

From 1:00 to 2:05 he is non stop welding. The heat is Nothing to worry about with 3s lipo and nickel.


“Despacito” in all your videos? Please have mercy



I just did a quick update video of my DIY ATV battery powered spot welder. All of this easily built for less than £20!!

I’ve made hundreds of welds since building it and it’s still going strong…


That’s cool, Kevin! Seems like you’ve got the timing down pat

What thickness nickel strips are you using in that video?


12mm x 0.15mm rated for 40A


It seems lee is gonna sell overseas his ac welder. It was restricted to korea.
Actually the boss welder has been restricted to korea for two years too.
I have Nothing to say about it as I don’t know how it works.


Hey, I finally found spare time to test the spot welder. :slight_smile:

It’s FREAKY amazing !
Nevertheless, I didn’t understand how to use the button, it only triggers automatically when I’m touching the pencil to the strip.
Sorry if you already told it…


Hey bro. You got there :blush:
What button are you talking about?


The little button which shall be connected to both pins free near to the XT90 pencil plug.
Someone replaced it by a pedal IIRC.


Its set to automatic by default, you need to set it to manual.


watch it again. as chinzw said the machine is automatic by default A icon. To use the button or pedal you need to change it to manual mode. lightning icon. 2:05 in the video. when the lightning is blinking and both electrodes touch the metal it will work as soon as you press the momentary button.
Make sure the lightning is blinking and both electrodes touch the metal. It can be tricky sometimes.


You can leave the button, just add the pedal wiring to the pins on the other side of the button


I just sent him a payment :slight_smile:


Welcome to the club. :grin:


Hey guys. I need some help with making a battery pack with the 18650 batteries.
I have the batteries and have the nickel tabs to solder to them but am lacking a soldering device and a battery management PCB. It needs to be the unchanged 3.7 voltage and I need to run a Mini male USB wire from it, and be able to charge the pack with it.

If anyone lives in Toronto or GTA and is willing to help out with it I’ll pay you… If you have some sort of knowledge on battery power management PCBs and which ones are good it would be best.

Contact me at

I am obviously willing to come to your place to get this stuff done…

Thanks !!!


Checked the video, it’s very well explained, thanks a lot !
(I should have searched a bit more before posting).

BTW, I noticed SOMETHING in your video

Are you from Bretagne ??? :astonished: :stuck_out_tongue: :heart_eyes: