Don't try this at home....Or should I????

[Dave Lehnert]

Any thought on this method to revive old drill batteries.

http://www.instructables.com/id/Revive-Nicad-Batteries-by-Zapping-with-a-Welder

[GERALD HARGROVE]

I will stick with taking my batteries to Batteries Plus and letting them deal with it. The key is the warning.

[David DeCristoforo]

This is the part I like:

WARNING:
If you get killed by a poisonous explosion it means you did something wrong.
Electrocution is a real possibility also.
Ask your parents how to not electrocute yourself with a welder.

[Jerome Hanby]

I don't think I'd use a welder, but using a 12 volt DC source for zapping cells can work. It's not going to be the miracle you're hoping for, but it might get a pack back in operation. I'd put a big red x on any cells you end up zapping to fix so you know where to start looking when the pack fails again.

On the other hand, you can find some pretty sweet deals on NiMH sub C cells (sub c cells are what all my packs are made of). A few cells and a little soldiering could give you a really stout pack, better than brand new. Just keep in mind each cell is 1.2 volts and shop accordingly. Also for some reason, all the bulk buys I've ever seen on sub C cells never add up to 18 or 24 volts, you always have a few too many or need a couple of more...

Don't mix Ni-cads and NiMH. Don't think it's dangerous, but it could be pretty erratic charging and discharging.

One last caveat, if your charger is really cheap (my B&D Firestorm chargers are in that category), you may need to add a current limiting resistor to keep from frying the charger. I haven't tested it, but I suspect that the NiMH cells will attempt to draw more current (basing that on greater output means greater input, but that's purely a guess, I may be all wet).

[ernie henshaw]

i did it with my mig welder on very low setting.had little to no sucess with reviving batteries.but i'm still here that's a victory right.

[Don Abele]

I don't care how expensive batteries become - I would NEVER do that. You're asking for an explosion. Nothing is worth that risk.

When my batteries needed to be replaced I sent them to mtobattery. Turn-around was quick, price was great, and there was a HUGE improvement in battery power/life (even over my new OEM batteries).

Be well,

Doc

[John McClanahan]

I have zapped Ni-cad batteries with an adjustable voltage / amperage power supply with mixed results. Sometimes I can get a little more use out of the battery, sometimes they are too far gone.

I would NEVER use a welder to boost a battery! I only did it using a power supply that I could control and monitor.

Boosting a battery this way can cause a bad cell to boil internally, creating pressure resulting in a steam and chemical explosion!

John

[Dan Friedrichs]

I have zapped Ni-cad batteries with an adjustable voltage / amperage power supply with mixed results. Sometimes I can get a little more use out of the battery, sometimes they are too far gone.

I would NEVER use a welder to boost a battery! I only did it using a power supply that I could control and monitor.

Boosting a battery this way can cause a bad cell to boil internally, creating pressure resulting in a steam and chemical explosion!

John

Ditto.

I've done it with a power supply before, had mixed results, and won't do it again.

[John Lucas]

It reminds me of an experience I had 50 years ago with some geniouses at a lab who called me up to get pictures of an experiment they were doing in creating a liquid acetylene tank. Acetylene was and is now stored in liquid form in a tank filled with sand like sediment. They keep the liquid from jostling around and being dangerous. But it is that sand like stuff that is so much weight to the product -- a waste for sure by these engineers. Anyway they had developed a tank that had a series of baffles that minimize sloshing. The DOT regs for testing tankage had a 10 ft drop test. So they had me set up my camera and then join them in the block house. I was using a fastex camera that shot 14,000 frames a second so I couldnt wait too long for them to count down...in fact when they said "2" I started the camera. Everything came off like clockwork. I had not been able to view the experiment thru the port hole...I was busy with camera. So we went t see what was there after the dust settled...that alone should have been a clue. There was nothing...I say again ...nothing. Parts of the tanks came back to us from neighborine counties. They may have put something in space long before NASA.