Revive Nicad Batteries by Zapping with a Welder

Step 6 Zapping Individual Cells

Pete Lynn dropped this battery pack in salt water. It shorted out the cells and it has been fully dead for a year or so. We peeled it apart to get at the individual cells. We scraped the salty cardboard off them and zapped them with a car battery. After that it worked fine.
It's easier to zap an individual cell than the whole pack at once.
Sometimes you can't revive a cell. You can cut or unsolder it from the others and replace it with a good one.

Comments

[tverstraete1]

Glad I found this!! I used my battery charger/booster set on the 50amp boost setting. Ran it over the terminals for the 18v ryobi's that have not charged in nearly two years and I now have them charging to nearly full capacity!!!

I also have some newer One+ 18v batteries that were starting to go bad (not hold a charge) and I did one of those (just being cautious) and it is working so much better now.

Thank you!!

[gilmo1938]

I've had a set of "useless" tools for about 3 yrs! till I ran across this site. I used the battery charger method and "zapped" one of my 14.4 batteries. O M G!!!!!! it worked, I just finished blinding myself when I tried to see if my flashlight would work after the zapping. I will zap my other bat when I get off duty Wednesday. I just want to say thank you for being different!

[pluckyduck]

I just tried this using a car battery charger that can do manual charging at 2 or 10 volts.  I didn't think it would work on a 14.4 battery pack but after about 30 taps at 10 volts the battery now takes a proper charge.  This is awesome, I will now have about 20 batteries!  I have been buying "functional" ones of ebay for years and they never lasted longer than a year or so before failing.

[mtwcbear]

Can you tell me which terminal is pos and which is neg on a black & decker 14.4 volt batt?? Thanks.

[lilpepsikraker]

Check with a multimeter. Mine costed $6 at a Ham Radio meeting/festival a few years ago. It's a GB Instruments, and it sure the hell is better than my dad's craftsman multimeter. Sometimes you get more for what you pay.

[uncmartin05]

I HAVE A 19.2 CRAFTSMAN THE BATTERY HAS 4 PRONGS SO WHITCH IS POSITIVE AND WHITCH IS NEG.

[tazmaniac_37752]

their should only be one negative those others are probably positives for different voltages so the drill can be variable speed a resisytor on 19 volts would probably get fairly hot!

[ReCreate]

[Arbitror]

LOL! that's awesome!

[ReCreate]

Haha,Yeah.

[travis7s]

If there is no markings you can use a voltmeter to see.

[jrivera]

i want to know the answer to that one too. i have 3 craftsman batterys that has the four proungs..

[dombeef]

Well for a start the third one is ground

[strmrnnr]

Since with DC (-) is the ground, I would have to say the craftman batteries are likely made of two cell wired together inside the drill housing. Two positive, two negative.

[dombeef]

Oh ok

[wheatstone]

I've seen this in a Mechanics Illustrated issue, In their project they hooked up the positive to a file and dragged a wire across the file because it has rough edges and gave a somewhat on off effect. ( Lots of sparks) This caused the hard batteries to get dusted off a bit more.