Reviving dead NiCad batteries with a welder

[Auzivision]

Reviving dead NiCad batteries with a welder

Has anyone around here ever tried this?

At first I thought it might just be an urban legend, but now I’m beginning to wonder.

Following are a few links on the topic:

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

http://www.ehow.com/how_5040729_revive-nicd-batteries.html

http://lumberjocks.com/topics/4334

http://www.handymanclub.com/community/Forums.aspx?g=posts&t=42166

 

[slicktoptt]

Yes, in fact I did it this weekend with an 18 volt Ryobi battery. Measured it initially at 16 volts. Used a spare Harbor Freight welder and not my Miller. Zapped it in reverse polarity a couple of times and then switched it and zapped a few more. Measured 18 volts and then charged it up. Seems to be working fine.

 

[tyrell2004]

Looks like it works, from all those links anyway.
Can you use a 12V battery charger for lower voltage batteries?
And positive to Positive? Seems like some guys are doing reverse polarity. I have a bunch of dead "D" cell rechargeable Maglite Flashlights I wanna try this on.

 

[GeorgiaHybrid]

Crank your welder up and do not reverse the polarity. I use a short (2'-0") piece of 12-2 wire that I soldered some aligator clips onto the end of it to attach to the battery and bared the wire on the other end for the welder. The batteries will not hold a charge as long as a newer one but will give you some additional time to work with them.

The crystal path that caused the original short in the cell will come back (sometimes after 1 or 2 charge cycles) and you can pop it with your welder again but each time you boost it, the life will get a little shorter. As a stop gap measure, it works on around 2/3 of the batteries I have tried it on.

 

[Tman]

Been discussed on the HAMB

http://www.jalopyjournal.com/forum/showthread.php?t=322721

 

[Privatejoker]

I've heard of doing that by discharging a capacitor. It treats the short like a fuse, basically.

 

[snapmom]

I did the reverse polarity using a 12V lawn batt. on my 14.4v nicad, time about 3 or 4 sec. it did the job, the batt works like a new one.

 

[35mastr]

I use this method just as described on the HAMB link. It works for some,But not on all batteries. I did 2 12 Volt Dewalt batteries not long ago. One will charge right up. But the other is junk.

 

[Tscott]

It does work. The reason the batteries die is that as the battery ages, the materials inside begin to crystallize. Over time these crystals grow to the point that they short out the cell. All you are doing by zapping them is running a lot of current through the small crystal bridge that has formed. This heats the bridge and burns up the crystals which eliminates the short. The short will eventually return as the crystal continues to grow, but it does indeed work.

Tom

Oh, I alos believe it only works on NiCab batteries.

 

[gc427]

Cool info. I will have to try this.

 

[sanddrag]

I've got a Dewalt 9.6V that won't take a charge. I've got to try this.

 

[NUTTSGT]

With my luck the battery would explode.

 

[Auzivision]

I kind of got a kick out of the disclaimer...

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.

Somehow, I don't see this fitting the average profile around here.

 

[54FordPanel]

I kind of got a kick out of the disclaimer...

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.

Somehow, I don't see this fitting the average profile around here.

How do you electrocute yourself with a welder?

 

[NUTTSGT]

How do you electrocute yourself with a welder?

Anything that uses enough electric to melt steel can kill you.

http://www.msha.gov/Accident_Prevention/Tips/shock.pdf

 

[sams]

welders use about 70 Volts, so unless you have a problem or just came out of a salt water pool you will be fine. The battery popping is a biger threat here. Everyone here please wear a facesheild when doing this please!

 

[sams]

you guys might find this thead interesting:

http://www.garagejournal.com/forum/showthread.php?p=855238#post855238

I find even brand new ni-cads to be too poor in performance for my liking.

 

[Shadowdog500]

An arc welder can electrocute you so don't loose respect for your equipment. Google arc welding electrocution and read about people who have been killed.

 

[916matt]

welders use about 70 Volts, so unless you have a problem or just came out of a salt water pool you will be fine. The battery popping is a biger threat here. Everyone here please wear a facesheild when doing this please!

its not the voltage you have to worry about. its the amperage that gets you. 75-100 mA can make your heart fibrillate. thats 75-100 thousandths of 1 amp. makes me think twice when im working on 8000A equipment at work.

 

[sams]

err no that's not how it works. Without the potential difference the current can't flow. The safe level a human body can take under normal conditions is 30 mA. This is why you can touch a car battery that can output 500 amps and not feel a thing. You need the voltage to overcome the internal resistance of your body otherwise there is no current flow. I have touched an elecrode off an erc welder while being earthed and while it's a bit unpleasant it was no worse than when I touched 32V AC.

The taught me all this stuff during my 4 years of electrical training. Off topic I know but is it true in the U.S anyone can wire up a building legally?

 

[Shadowdog500]

In my area the home owner can run thier own electric. The building inspector is also pretty good at giving your stuff a really good checkout.

Go online and look, there are multiple reports of people getting killed with arc welders. In the cases I read they were ussally soaked in sweat, but it does happen.

Chris

 

[mslisaj]

It worked for me. I wore safety goggles and used a brake drum for a scatter shield if one decided to explode.
My Ryobie's came back for a year and I did it again. My Sears batteries wouldn't recover. But it does work well.
Lisa

 

[MacMan]

Tried this with my SIP Migmate 150 on two very tired cordless drill batteries. Yet to do any significant work with the drill to see if I can have more than 3 minutes use per battery.