Intro: Spot Welder for Lithium-ion 18650 Battery Tutorial
Easy to build DIY spot welder for under 60$.
Works great und safes a lot of time.
High temperature destroys lithium batteries, so soldering is no option.
I want to build a 700Wh battery pack for my electric homemade boat and E-bike using 60 panasonic ncr18650b lithium batteries.
Step 1: Watch the Video! Check Schematics for the List of Material
Thats all you need:
1 x resistor 1k
1 x resistor 10k
1 x foot switch
1 x Hifi Cap min. 1F
8 x MOSFET IRF1404
1m copper cable 2.5mm²
2m copper cable 35mm²
Total costs: about 60$
Step 2: Attach the MOSFETs and the Eyelets to the Copper Rails
Sand the copper rails for better
The eyelets are very easy to bend (watch the video)
Step 3: Wooden Base Plate and Copper Clamps
Attach the Hifi Cap to the wooden base plate.
Make the copper clamps for the 35mm² cable and the cap.
Use wodden distance plates to attach the copper rails with the FETs and eyelets.
Step 4: Solder GATE and SOURCE Pins
Solder eyelets to the SOUCE pins of the FETs.
Connect all GATE pins.
Dont´t foreget 10k resistor between GATE and SOURCE
and 1k resistor after the foot switch.
Step 5: Welding Cables and Connector
Connect one 35mm² welding cables to the plus pole oft he cap
and the second to the DRAIN copper rail.
I also installed a connector for the battery and the foot switch.
Step 6: Welding Tips
Use for the welding tips the 2.5mm² copper cable.
Stick the 2.5mm² copper cable into the 35mm² cable as shown in the video.
Now you are ready to do your first welding tests.
To load the Cap use a power supply or a 12V battery with a 60W lamp in series.
Benefit of the power supply: you can vary the amount of energy in the cap.