18 dead dewalt batteries....welder?

[stage20]

i buy and sell on the constant and end up with all kinds of stuff. i hoard them whenever i can get a deal on them. over the years they die or wont hold a charge unless they are hot. the last batch of 8 dead ones i had i traded to a local guy that was doing rebuilds for one good battery. win for me. i got a hot battery and he got plenty of cases to help in his profits.

ive watched several you tube vids of shocking these things with a welder to bring them back to life. personally, im scared to try it, but i know their are some educated people on here that could steer me the right direction.

i dont care about the batteries, they are already dead. i just dont want to harm myself or burn my shop down. lol.

 

[ScottsGT]

Turn on recorder.

Set down beer.

Say "Hey y'all, watch this!"

Hit batteries with welder.

If all goes wrong, profit by being Internet sensation.

If all goes good, you have charged batteries.

But hitting with high voltage, I have to wonder if they do work, for how long?

 

[Kaervak]

You don't need a welder, just a source of DC voltage. I used my battery charger set to 24v to do it. It won't bring a pack back to new, but it will put some life into them.

 

[jerseykat1]

Turn on recorder.

Set down beer.

Say "Hey y'all, watch this!"

Hit batteries with welder.

If all goes wrong, profit by being Internet sensation.

If all goes good, you have charged batteries.

But hitting with high voltage, I have to wonder if they do work, for how long?

Do what he said. Be sure to share the results here first. [emoji33]

Sent from my Nexus 6P using Tapatalk

 

[kunkernator]

You don't need a welder, just a source of DC voltage. I used my battery charger set to 24v to do it. It won't bring a pack back to new, but it will put some life into them.

Exactly. The whole idea behind it is to give it a little "jump start" kinda like jumping your car. In theory, a welder would do it, but a battery charger would be safer.

 

[rancherbill]

Don't do lithium batteries!

 

[stage20]

Don't do lithium batteries!

Correct. They will blow up. Nicad only

 

[TomB19]

Don't do lithium batteries!

It wouldn't be too bad, if he did it on a concrete surface while wearing gloves and a face mask. lol!

 

[Showkey]

Who still uses nicad batteries........

 

[kctyphoon]

Just hook two good 18v batteries in series. Hook on lead up to one terminal on the dead battery, and tap the other wire of the circuit to the other contact of the dead battery. If the battery doesn't have the polarity listed on the case, just google it..

You could even just put the battery on the charger, and quickly plug and unplug the charger into the wall.. I think the charger sends like 50v into the batteries to charge them.. Both methods have worked for me in the past.. This doesn't work for all batteries. If the cell/cells are bad. - it's done..

This usually just works on batteries that have discharged down so low, that the charger thinks they are bad..

 

[stage20]

Who still uses nicad batteries........

Broke folks

 

[ovrrdrive]

Any battery same voltage or slightly higher will work. What happens is the batteries get so dead the charger won't detect they have been plugged in and won't start the charge. By hooking them up to a known good battery they'll take a small charge from the other battery and then the charger will kick on and complete the charge. There's no magic in using a welder. I've jumped them from as little as a minute of charge from another battery.

 

[rslaback]

I think you guys are talking about two different things. The welder trick isn't used to put a bit of charge into the batteries so that the charger will charge them. The welder (or higher voltage) trick is done to burn off the finger like crystal dendrites inside the cells which are shorting out the cells. Burning them off allows the battery to take a charge again until they regrow.

 

[Loscaldazar]

But hitting with high voltage, I have to wonder if they do work, for how long?

Technically it's low voltage and high amps, which is why this works sometimes. A 120V welder won't output over 30 volts (if even that), but they can hit 140 Amps.

 

[rancherbill]

Who still uses nicad batteries........

Lots of people have a big investment in tools. There's a ton of NiCad / NiMh tools out there. It's cheaper to rejuvenate/rebuild or buy a new battery rather than replace all the tools.

 

[sleepy127]

I think you guys are talking about two different things. The welder trick isn't used to put a bit of charge into the batteries so that the charger will charge them. The welder (or higher voltage) trick is done to burn off the finger like crystal dendrites inside the cells which are shorting out the cells. Burning them off allows the battery to take a charge again until they regrow.

More info on how to do this? What precautions to take?

 

[ScottsGT]

Technically it's low voltage and high amps, which is why this works sometimes. A 120V welder won't output over 30 volts (if even that), but they can hit 140 Amps.

Thanks! Great info to know. I've never looked into the volts/amps a welder puts out. I guess we're talking about a stick welder here too? Hard to do with a MIG or a TIG.

 

[AA/FC]

Thanks! Great info to know. I've never looked into the volts/amps a welder puts out. I guess we're talking about a stick welder here too? Hard to do with a MIG or a TIG.

We did it years ago with a TIG all the time. If I remember correctly, we disconnected the tig torch from the machine and used another ground clamp in its place..... so basically 2 ground clamps. Then just hit the foot pedal for a few seconds and presto, functioning battery. (This was a friends welder, he did the connections)

As far as welder voltage is concerned..... remember, in electricity, when voltage goes down amperage goes up. This is how a welder can put out 250 amps (for example) while plugged into a 50 amp outlet. The welder drops the voltage down, amps go up. In fact, a lot of the new welders with digital display will show the voltage along with amperage.

 

[gungatim]

I think you guys are talking about two different things. The welder trick isn't used to put a bit of charge into the batteries so that the charger will charge them. The welder (or higher voltage) trick is done to burn off the finger like crystal dendrites inside the cells which are shorting out the cells. Burning them off allows the battery to take a charge again until they regrow.

yep, same as de-sulfating a lead acid wet cell. can work on some batteries but not on all of them if they are too far gone...

 

[stage20]

I think you guys are talking about two different things. The welder trick isn't used to put a bit of charge into the batteries so that the charger will charge them. The welder (or higher voltage) trick is done to burn off the finger like crystal dendrites inside the cells which are shorting out the cells. Burning them off allows the battery to take a charge again until they regrow.

yes.

the acid crystallizes so to speak and the high shock excites the cells.

edit (from what i have read)