Welding with jumper cables and batteries

[sewerzuk]

I threw together this short video demonstrating the setup for stick welding with a set of jumper cables and a pair of batteries. This isn't intended as a replacement for a shop welder, but it does work as a trail/roadside repair. I've used this method dozens of times to weld up link mounts, spring hangers, a cracked wheel, cracked frames, drag links, etc. There are, of course, alternate methods of mobile welders but the jumper cable/battery method is super cheap, easy to set up, and consists of tools and materials that almost everybody already has.
I do own a ready welder, but I find that I usually just toss a few sticks of welding rod in my toolbox to save on space and weight. If I know that I will be doing some welding, then I'll bring along the ready welder...but it stays in the shop and pulls spoolgun duty for my MIG welder most of the time.

Stick welding with batteries is a little different than welding with a standard stick welding power supply (AC or DC). Normally, a stick welder would be constant current...meaning that, you select and amperage and the power supply maintains that. Using batteries means that you are using a constant voltage source...the current varies based on how close you hold the welding rod to the weld puddle. Controlling electrode height is critical...it takes some practice. Because batteries are capable of supplying so much current, the rod almost never sticks like it does when welding with a conventional power supply (it can stick if the batteries are discharged, or if you have a loose connection). Even if you are an experienced stick welder, you should practice this once or twice before relying on it out on the trail.

The welding in this video was done with 1/8" 6011 rod, but others work well too. I usually just take a few sticks of 6011; it is a good general-purpose rod that works well for most types of trail repairs. If you know that you're going to be welding some cast iron, stainless, high carbon, or something else, then you should select the proper electrode...
I've seen people use coat hangers, coins, etc. as a filler rod and I've tried it a few times; but without flux, you end up with a pretty nasty bird-poopy looking weld. Its easier to be a little proactive and toss some welding rod in your toolbox...

It should be obvious, but I'll state it anyway. Wear the proper protective gear. You have 1 set of eyes...don't try to weld with a set of your favorite oakleys. Using the batteries as a power source offers its own set of risks as well...I have logged many hours of arc time using batteries as a power source and never had a problem, but keep this in mind:
-Batteries offgas an explosive mixture of Hydrogen and Oxygen when being charged. A welding arc can ignite this gas and blow battery acid all over the place. Just be sure you don't weld where sparks can drop on the batteries, and you're in a well ventilated area
-A direct short across a 24v battery bank with heavy gauge jumper cables will melt battery terminals, the jumper cables, and your hand. Batteries are capable of producing more than 600 amps when fully charged...that's a LOT of current. Make sure you don't accidentally create a short when you're hooking everything up
-Disconnect the batteries from the vehicle if possible. A welding arc generates large voltage spikes and noise...although the rectifier/regulator in an alternator is fairly rugged, there are dozens of little microelectronic circuits all over the vehicle that aren't so rugged. You don't want to destroy a $1000 ECU/PCM/whatever.
-Fully discharging lead-acid batteries shortens their life significantly. If you're going to try this, make sure that you don't allow the batteries to become discharged during welding, and make sure to recharge them after you are done. Batteries will last a long time if properly cared for, even if you use them for welding.

Stick welding using standalone batteries:
Welding with jumper cables and a pair of batteries - YouTube

Stick welding using a vehicle with a 24v electrical system:
Welding with jumper cables and my Deuce and a Half - YouTube

 

[Scrambler82]

Good vid.
Well presented.

I have seen welding on the trail using this method but no one explained it as well as your vid did.

Thks

 

[jake98]

I wonder how it would do with just one battery..

 

[deereman75]

great video, very well made, very good advice. If you were going to be doing a lot of welds that way, you might want to make up some welding leads with jumper cable clamps on one side, and a stinger and ground clamp on the other side, might work better than vise grips, but that all would take up more space.

 

[sewerzuk]

I wonder how it would do with just one battery..

I've tried 1 battery and some 1/16" rod...just not enough arc to work with. I have thought about experimenting with 6 volt batteries, so I could get 18v, 24v, 30v, etc. But, I've never really had a reason to try it...2 batteries has always worked just fine.

 

[k0ua]

Not only are you a pretty good welder, you are a pretty good presenter.
well done.

James K0UA

 

[rankrank1]

I agree that welding with the batteries should not hurt them unless you were to accidentally stick a rod. I think I would also invest in a cheap HF $4 clamp type stinger so I could quickly and easily unclamp the rod if I were to accidentally stick one.

It is nice to see that 2 batteries works though. Most homeowner grade real arc welders have 79 volts Open Circuit Voltage to help with initial arc strike (80 is the cap limit on OCV by Underwriter Laboraties to keep people from electrocuting themselves). The arc voltage falls to roughly 30 volts when the actual welding is occuring.

Here is another nicely put together video (not mine) on using 3 car batteries. With 3 car batteries you are slightly over the theoretical ideal voltage for arc welding but initial arc strikes should be easier. With 2 batteries you are slightly under the theoretical ideal voltage to arc weld.

Arc Welding with 3 Car Batteries (Tutorial & Demo) - YouTube

 

[sewerzuk]

I agree that welding with the batteries should not hurt them unless you were to accidentally stick a rod. I think I would also invest in a cheap HF $4 clamp type stinger so I could quickly and easily unclamp the rod if I were to accidentally stick one.

It is nice to see that 2 batteries works though. Most homeowner grade real arc welders have 79 volts Open Circuit Voltage to help with initial arc strike (80 is the cap limit on OCV by Underwriter Laboraties to keep people from electrocuting themselves). The arc voltage falls to roughly 30 volts when the actual welding is occuring.

Here is another nicely put together video (not mine) on using 3 car batteries. With 3 car batteries you are slightly over the theoretical ideal voltage for arc welding but initial arc strikes should be easier. With 2 batteries you are slightly under the theoretical ideal voltage to arc weld.

Arc Welding with 3 Car Batteries (Tutorial & Demo) - YouTube

Agreed...the stinger is a good idea, especially if a person was intending to use this more often than once or twice a year.

When I first tried this I used 3 batteries; IMO the arc was too hot for "most" jobs. Really easy to burn through 1/4" material. I could see it being necessary for thicker metal, but I've never had a reason to weld 1/2" or thicker outside of my shop...but all of the times I have used this technique it was on a 4x4 jeep/truck/etc. Repairing heavy equipment would surely present a person with the need to weld on thicker material.

Since the car batteries are capable of supplying 600 (or more) amps, its actually really difficult to stick the welding rod, and not too difficult to strike the arc. I would say it is much easier to strike the arc with batteries/jumper cables than with a CC power supply...the deeper you push the rod into the weld puddle, the hotter the arc gets!

 

[Short Game]

...but keep this in mind:
-Batteries offgas an explosive mixture of Hydrogen and Oxygen when being charged.

I believe the same is true of a fast discharge.

 

[yomax4]

I am surprised that some one out there actually gears up for this type of welding. I mean, You throw some rods in the tool box in case...? Cool that it works and I know it's been done with battery chargers, But still.