# Zapping NiCad Batteries... Does it work?



## wdestar (Jul 19, 2008)

I've got 2 different brands of cordless drills that used to function very well. Problem is, the batteries on one brand are weak and completely dead on the other.

I've read on the internet that they can be zapped (into restoration) with a mig welder. I don't have a mig welder. Does anyone have a formula for zapping such with an alternative DC suppy... i.,e. - place x amount of DC volts for y amount battery voltage?

And finally, does it work?

Thanks:001_huh:


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## BuzzKill (Oct 27, 2008)

Have you tried to microwave them? If not that just throw them into a fire.


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## blueheels2 (Apr 22, 2009)

Try it and videotape it. Then show us.


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## sparky.jp (May 1, 2009)

see this thread:

http://www.electriciantalk.com/f2/18volt-batteries-9958/

The 'search' function is your friend! :thumbsup:


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## gilbequick (Oct 6, 2007)

Holy crap, what's up with people being so rude lately? Not just this thread but many others. Forums are for help and discussion, not ridicule and being an a$$hole. It's getting ridiculous.


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## AussieApprentice (Aug 16, 2008)

gilbequick said:


> Holy crap, what's up with people being so rude lately? Not just this thread but many others. Forums are for help and discussion, not ridicule and being an a$$hole. It's getting ridiculous.


I feel the same. Have not posted a few times because I can't be bothered because threads are going off topic.


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## B4T (Feb 10, 2009)

Threads always go off topic.. keeps it interesting :thumbsup:

There are all kinds of ideas floating around that will get you in trouble :no:

Battery chargers are the only way to make them recharged.. same as your car battery.


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## Dennis Alwon (May 9, 2009)

Black4Truck said:


> Threads always go off topic.. keeps it interesting :thumbsup:


I agree but the negativity told other posters is totally unnecessary. People come here for help and they get responses such as " Call an electrician". Sometimes these are beginners that are trying to learn something to impress their boss. No need for that crap.


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## B4T (Feb 10, 2009)

Dennis Alwon said:


> I agree but the negativity told other posters is totally unnecessary. People come here for help and they get responses such as " Call an electrician". Sometimes these are beginners that are trying to learn something to impress their boss. No need for that crap.


Sometimes it's hard to tell the DIY guys from the real EC looking for help.

I agree.. sometimes it is over the top and I am guilty of it also


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## AussieApprentice (Aug 16, 2008)

If the batteries are not working because they have not been used for a long time or have been overdischarged it is possible they may be restarted. Almost all tradesmans cordless tool batteries can not be rejuvenated once they die.

Do not run your batteries down below 1.0v per cell (about where the drill starts to slow down) as that can damage them.

Keep them charged. Don't be afraid to top them up. Don't charge them when they are hot.

If you have a current limited DC power supply you can try charging them at 1.5v per cell and current limited to 1.0A for an hour. That amount of current should be safe for most cordless battery cells. If that does not get them going they should be scrapped.


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## blueheels2 (Apr 22, 2009)

My apologies, I didn't mean to come off like a douche.


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## KayJay (Jan 20, 2008)

wdestar said:


> I've got 2 different brands of cordless drills that used to function very well. Problem is, the batteries on one brand are weak and completely dead on the other.
> 
> I've read on the internet that they can be zapped (into restoration) with a mig welder. I don't have a mig welder. Does anyone have a formula for zapping such with an alternative DC suppy... i.,e. - place x amount of DC volts for y amount battery voltage?
> 
> ...


 I had minimal success using the freezer method with a pile of old 18V Dewalt batteries. I sealed them in a Ziploc bags and put them in the freezer overnight. The next morning I smacked them hard against the workbench to supposedly break up the hair-like crystals that form inside the cells. After bringing them up to room temp and recharging, two out of six batteries actually held a partial charge for a couple of days afterward, but they were still basically dead batteries. I ended up keeping only one of them to use in my Dewalt radio just to prevent the memory presets from draining the two AA batteries inside the radio.

I didn’t have any luck when attempting to connect two good XRP batteries in series to zap a weak battery pack back to life.
I’d never thought of using my MIG welder for the purpose, but I don’t know if it would work anyway, since it’s only rated at around 21 VDC output.


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## miller_elex (Jan 25, 2008)

I heard about zapping the dead batteries too.

I took apart one battery, and found they are really C-cells stacked inside. It was a gooey mess by the time I got them back together. I shipped it off to Volt-man to be rebuilt about four years ago.

The voltman rebuild worked fine, but I suspect they only change some of the cells. It didn't last as long as a new battery. No disrespect to voltman, maybe there was a bad battery mixed in.

Now I wait until ACME has there big 18V battery sale, because working with crap batteries makes the day much longer! P.S. I am not a contractor and don't supply my own batteries except for my own enjoyment.


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## kbsparky (Sep 20, 2007)

I learned the hard way: Do NOT put your deWalt batteries in the freezer!

Did that once, and it died completely the next day. Never again ....


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## RIVETER (Sep 26, 2009)

*Zapping batteries*



wdestar said:


> I've got 2 different brands of cordless drills that used to function very well. Problem is, the batteries on one brand are weak and completely dead on the other.
> 
> I've read on the internet that they can be zapped (into restoration) with a mig welder. I don't have a mig welder. Does anyone have a formula for zapping such with an alternative DC suppy... i.,e. - place x amount of DC volts for y amount battery voltage?
> 
> ...


No, it usually does not. You first must try to trickle charge the battery for, maybe a day, or so, and after that if it does not work you could possibly take it apart and find which one...or more of the cells are bad, and then replace them. Pretty labor intensive, but fun to get one going.


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## BuzzKill (Oct 27, 2008)

I still say microwave them and/or throw them in the fire, but I guess that's just me.


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## RIVETER (Sep 26, 2009)

*Batteries*



BuzzKill said:


> I still say microwave them and/or throw them in the fire, but I guess that's just me.


If you do decide to microwave your batteries, you have to put a WET paper towel over it so that when it explodes it won't get all over the insides.


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## BuzzKill (Oct 27, 2008)

RIVETER said:


> If you do decide to microwave your batteries, you have to put a WET paper towel over it so that when it explodes it won't get all over the insides.


 ooooh, that's an important step I forgot, thanks RIV!:thumbsup:
damn wife would KILL me if I f*cked up the micerwave.


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## RIVETER (Sep 26, 2009)

*kBatteries*



BuzzKill said:


> ooooh, that's an important step I forgot, thanks RIV!:thumbsup:
> damn wife would KILL me if I f*cked up the micerwave.


I was just kidding.


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## BuzzKill (Oct 27, 2008)

RIVETER said:


> I was just kidding.


 I was just kidding too.


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## Animal103 (Apr 5, 2012)

I have herd of zapping the batteries in the last few days AND i have done it to one of my very poor weak drill batteries didnt have a welder though so i charged one battery for my drill and took the other battery apart then used the 18 volts in the still together battery to zapp each cell one at a time and without ending up in hospital results so far are more power at the moment ime leaving the battery overnight to see if it holds its charge as it doesnt do overnight ever at all b4 zapping my volts on a full charge were 18.27v after zapping and a full one hour charge my volts are now 19.76v and still strong after 3 hours so far but we will see if it works for the memory affect of the battery ime not sure it will but worth a try as its a free fix to something that would other wise go in the bin will let ya know what happens in the future


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## drsparky (Nov 13, 2008)

A Ni-cad battery can/will develop a memory. A "zap" will brake down a hole in layer of insulation and they will work again somewhat. If you open the case you will find a bunch of cells soldered together in series. Use your electricians skills and a meter and you will find one of the cells is dead, most will be good. Rebuild your battery pack from a pile of bad ones an you will be an electrical hero.


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## khfiei (Aug 20, 2011)

After identifying a defective cell as noted in the other posts, the best way to "zap" individual nicad cells (1.2 V) is to use a large (30 to 50-volt DC) capacitor with a DC power supply. Charge the capacitor from the power supply, disconnect from the supply, then discharge the capacitor across the SINGLE cell. This provides a short duration, high current pulse that usually restores the cell. Just be prepared, as the arcing produced when contact is first made can be startling. Higher energy setups (1/2CV^2), will remove almost any short. Multiple discharges may be necessary for lower energy setups.


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