DC arc welder restores sulfated golf cart batteries.

[Cujet]

I can't believe it actually worked.

My lightly used airport 48V golf cart had new batteries about 5 years ago (batts dated 2018). As expected, the range and speed declined over time until the useless thing sat unused for the last two years, as the batteries would not charge with the finicky digital charger.

A year ago, I tried using various tricks to get some power into each 8V battery (they were showing 0.54V to 2V) Then hooking up the cart's charger and so on. Best I got was about 2-3 minutes use, then they'd go dead.

After watching a YouTube video about using an Arc Welder to desulfate flooded lead acid batteries, I thought I'd give it a try. Using care to get a spark free connection. A fan to blow away tons of explosive fumes and a 5 minute limit, I followed the procedure.

Note the DC TIG welder's ground is POSITIVE. So that's where it goes. Started at 10A, until each cell boiled, then 50A for 4 minutes and 100A for a minute, boiling like crazy, a few cells boiled over so I backed it down and up again to reduce losses. That's it, as repeated "zapping" did not seem to be necessary. As each 8V battery was showing 8.4V or so.

Hooked up the charger, and they charged normally. Battery measures at 80% after a number of miles, and 50.4V, or 95% in the morning, after charging and disconnecting overnight. I believe it restored the batteries, as I can now drive it all over the place, down dirt roads, top speed runs, (it goes 30)

Success

 

[SubLGT]

.........Started at 10A, until each cell boiled, then 50A for 4 minutes and 100A for a minute, boiling like crazy, a few cells boiled over so I backed it down and up again to reduce losses.....

What voltage?

 

[f355spider]

 

[LongTime_Lurker]

You're flirting with danger!

 

[f355spider]

You're flirting with danger!

I'd definitely do this outside and wear safety glasses and other PPE to protect myself

 

[oldgrayman]

Face shield .

 

[Cujet]

You're flirting with danger!

Correct, I used the fan to reduce the chance of accumulated hydrogen gas. I also screwed on long wires to the terminals (I did not use clamps), and remotely hooked up my welder. That way, there was no chance of a spark. The terminals were clean.


Golf cart was outside, welder inside. Welder is a Syncrowave 180, with variable amps and set to DC, stick weld. Turned on and off from the welder. I wore goggles and had a hose ready in case something happened. Stood back just in case.

What voltage?

Not sure on the voltage, I did not want a meter hooked to the battery during this, just in case acid went everywhere. On the videos I've seen, they measured the voltage somewhere under 20V. Clearly, it's high enough to PUSH plenty of current through a sulfated battery.

Just drove 15 miles, no issues what so ever. I still can't believe it. The thing still hit top speed at the end of the drive. Plenty of power left. I'd say the 95% voltage/capacity reading I get is accurate.

 

[Brad_C]

Sounds like you blew the sulfated surface off the plates. You'll probably find more sludge in the pit under the plates and a reduced capacity, but when compared to useless high resistance sulfated batteries it sounds like a win to me.

 

[Cujet]

Sounds like you blew the sulfated surface off the plates. You'll probably find more sludge in the pit under the plates and a reduced capacity, but when compared to useless high resistance sulfated batteries it sounds like a win to me.

I'm driving it about 20 miles around the neighborhood, even made it home from the other side of Jupiter Farms on a semi-flat tire last night. The range is very close to what it could do before with generally healthy batteries. The batteries measure at 95% and so far, I am in utter disbelief.

I'm sure you are right, there is likely to be some "debris" at the bottom of the cells. I've been driving on washboard dirt roads and maybe this settles the junk to the bottom?