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Boss level custom spot welder


actually is not easy to do. You need 4s to weld nickel on copper and the welds are acceptable but not as strong as copper on steel. Copper on copper is even worse therefore the best way with copper is the wide tabs method.


i just tested it for you.
to do 0.1 nickel on copper you need 3.5-4ms on 4s
to do 0.15 nickel on copper you need 6-7ms on 4s
i am low on pure so i used plated and didn’t test 0.2. I guess 0.2 can be done with 7-8ms.
As seen on video plated is not a good idea. Use only pure for that


Thanks rojitor! I couldn’t make out the details, but those look like your 4s batteries.

I"ll get some 4s to test when my welder gets here too. But now I’m planning to only spot weld the nickel on the battery. For the other end, I can just solder the nickel to the copper bus.


You depleted the lipos twice for that pack? I thought the power comsumption was lower


The power comsumption is low but copper is some serious business…
The welds quality drop along with the voltage so I try to keep the battery fully charged as much as possible. I refilled twice but the cells were at 3.9-4v
I do not let them go below that when welding copper. Besides I give some rest to the machine while charging.
Nickel works better with low voltage. The same pack could probably be done with just one charge if I used nickel.


I am glad I’ve found this thread :slight_smile:


I am almost done editing a video of my last build.
I did this battery under 100 euro enclosure included.
I will upload as soon as I finish it.



Good Job. ^^


Thank you lee.


So I have just started trying to use this spot welder and am having problems with it.

  1. In manual mode trying to weld the sample nickel plated strip that came with it to a box cutter blade I need to use 16 ms x 4 pulses to get a solid weld.

  2. In automatic mode set for only 4 ms x 1 pulse, 4 out of 5 attempts it appears to just reboot. For battery power I am using two 3s 2.2 Ah 25C lipos in parallel - both are almost fully charged at 12.2 volts.

Is it just that my battery source is not good enough or did I get a dud?


What battery are you using have you checked setting for voltage?


Really weird. The voltage looks fine. 12v.
Try only one lipo. If you can borrow another lipo try it.
Check all wires
Check all settings. What’s your minimum voltage setting?




The reset, because the battery discharge rate is insufficient.

2x 3s 2.2 Ah 25C is similar to 3s 5A 25C.
But, current loss occurs at XT60 connector and 12 AWG wire(XT60-XT90).

  1. Direct connect the connectors(XT90-XT60). without 12AWG wires
  2. Switch to a more powerful battery.


Thanks - I will give those a try and report back with the results.


Hey @rojitor mind dropping a link to buy the full set


Check first post below “disclaimer” mail there


Hi der so is it possible to order this spot welder atm


See post above Jesus