Uploaded October 2020 | Updated September 2026, 1 week ago
After the failure of my $16 battery tab spot welder, I saw Kevin Dark's DIY version. But it wasn't exactly what I needed, so I decided to build a modified version.
The Modified Dark Welder, or Dark Welder 2, has a foot switch that triggers a precise welding current pulse that is always the same length of time - no matter how long you hold down the button.
And in my new version, the button is now a foot pedal to keep your hands free.
The best part is: IT WORKS!
Check out Kevin Dark's original welder: youtube.com/watch?v=o1NFbchHeM8
Kevin's channel: youtube.com/c/darkkevind1978
Also, don't miss his nifty 18650-powered DIY electric skateboard!
Goodies in the vid (some affiliate links):
- Capacitor Charge calculator: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html#c1
- Capacitor Discharge calculator: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html
- Starter Solenoid Relay: amzn.to/2Igv1jB
- Gebildet 2 Pieces Pedal Switch: amzn.to/3nJ3WoY
- 4700 uF 63V electrolytic capacitors: amzn.to/2SPy0RG
- Schottky 5A 100V diodes: amzn.to/3nM7R4y
- 150 ohm 2W resistors: amzn.to/3nLnlp4
- Copper nails: amzn.to/33QZ6xZ
- Lighted pushbutton switch: conrad.com/p/tru-components-tc-r13-527d2b-pushbutton-switch-14-v-dc-20-a-1-x-onoff-latch-1-pcs-1587919
- 12V, 10Ah, +150CCA lead acid battery: amzn.to/3eMsGZr
- 16mm^2 wire
- Large domino (screw terminals to hold welding cables + copper nails)
See the schematics at my web site:
scottiestech.info/2020/10/13/dark-welder-2-my-diy-battery-tab-spot-welder
More techie tips: scottiestech.info
After the failure of my $16 battery tab spot welder, I saw Kevin Dark's DIY version. But it wasn't exactly what I needed, so I decided to build a modified version.
The Modified Dark Welder, or Dark Welder 2, has a foot switch that triggers a precise welding current pulse that is always the same length of time - no matter how long you hold down the button.
And in my new version, the button is now a foot pedal to keep your hands free.
The best part is: IT WORKS!
Check out Kevin Dark's original welder: youtube.com/watch?v=o1NFbchHeM8
Kevin's channel: youtube.com/c/darkkevind1978
Also, don't miss his nifty 18650-powered DIY electric skateboard!
Goodies in the vid (some affiliate links):
- Capacitor Charge calculator: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capchg.html#c1
- Capacitor Discharge calculator: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html
- Starter Solenoid Relay: amzn.to/2Igv1jB
- Gebildet 2 Pieces Pedal Switch: amzn.to/3nJ3WoY
- 4700 uF 63V electrolytic capacitors: amzn.to/2SPy0RG
- Schottky 5A 100V diodes: amzn.to/3nM7R4y
- 150 ohm 2W resistors: amzn.to/3nLnlp4
- Copper nails: amzn.to/33QZ6xZ
- Lighted pushbutton switch: conrad.com/p/tru-components-tc-r13-527d2b-pushbutton-switch-14-v-dc-20-a-1-x-onoff-latch-1-pcs-1587919
- 12V, 10Ah, +150CCA lead acid battery: amzn.to/3eMsGZr
- 16mm^2 wire
- Large domino (screw terminals to hold welding cables + copper nails)
See the schematics at my web site:
scottiestech.info/2020/10/13/dark-welder-2-my-diy-battery-tab-spot-welder
More techie tips: scottiestech.info
