How to Make a Portable Welder With Two 12-Volt Batteries

Welding involves using electricity to melt and join two pieces of metal through a heating process. The amount of electricity required to melt metal can be found in most garages and even under the hood of many vehicles. Two 12-volt car batteries wired together in series will produce 24 volts of electricity, which is just enough electric power to provide a proper welding current to, for example, make repairs to a vehicle.

Things You'll Need

  • 2 batteries, 12 volt
  • 2 pairs of jumper cables
  • Locking pliers
  • Welding rod
  • Dark glasses
  • Clean rag
  • Brake cleaner
  • Wire the batteries in series. Place the batteries side by side of each other. Place the first pair of jumper cables from the negative terminal of battery "1" to the positive terminal of battery "2." You now have a 24-volt power source to weld with. Connect the second pair of jumper cables onto the positive terminal of battery "1" and on to the part to be welded, and the final jumper cable connects the negative terminal of battery "2" to the handle of your locking pliers. Clamp your welding rod into the jaws of your locking pliers.

  • Clean the part to be welded. Remove any dirt or mud, scrape away any paint or rust and use a clean rag and brake cleaner to wipe off any oil or grease.

  • Make your weld. Put on your dark glasses. Touch the tip of the welding rod to the metal you want to weld. Weld your parts.