Method to revive Ni-cad 12 volt Dewalt batteries

andy r · Nov 22, 2013

There is a guy selling a CD on ebay on how to renew Dewalt Ni-cad batteries that 1) won't charge 2) charger says are bad 3) won't hold a good charge 4) not fully charged. Has anyone seen this ad??? Does it work??? He says it is as easy as jump starting a car. I assume that he might be using a car battery and jumper cabes?? Anyone bought this CD? or know how to do it?? Thanks

waltdavies · Nov 22, 2013

I found the best way is to go to Batteries Plus and trade them in in on a new one.
Walt

Texasmark1 · Nov 22, 2013

I read up on it and to reset them you have to drain them down to some millivolt level. Did so over the process of a week and results were marginal. Bought Lithium ion batteries for the Ryobi tools and never looked back. Well worth the bucks.

Mark

rabbit-1 · Nov 22, 2013

Doesn"t it take a different charger for Li ion?

t1 · Nov 22, 2013

Yes, Lithium Ion batteries require a charger designed for them. the battery pack has electronics in it that tell the charger how things are going so that it doesn"t over charge, or overheat the batteries as they charge.

mkirsch · Nov 22, 2013

There is no way to reliably revive dead NiCd batteries. Once they're dead they're dead. If you revive them successfully, they weren't dead to begin with.

The CD is a scam.

Jiles · Nov 22, 2013

I had Six Ni-cad batteries that were 18v and Three that were 12V.
I simply drained them down completely and just brushed terminals with two small jumpers from a fully charged automotive 12V battery.
It revived two of the 18V and one of the 12V.
None of them would take a charge before this but Three will now charge and work.
You have very little to lose by trying.

NYCamper62 · Nov 22, 2013

ot - Not sure about the Dewalt charger but the Ryobi One+ charger does charge the older black-yellow NiC's.

JMOR · Nov 22, 2013

(quoted from post at 10:53:54 11/22/13) There is a guy selling a CD on ebay on how to renew Dewalt Ni-cad batteries that 1) won't charge 2) charger says are bad 3) won't hold a good charge 4) not fully charged. Has anyone seen this ad??? Does it work??? He says it is as easy as jump starting a car. I assume that he might be using a car battery and jumper cabes?? Anyone bought this CD? or know how to do it?? Thanks

eally needs to be done on each individual cell, not the cells in series. Trying to discharge the group, one will be discharged first & the remainder will try to reverse charge it!!! Next, while some can be recovered after discharge by a hard high current jolt, the results are short term & then back to no good. Done 50 or more before I decided that it does not pay. As some have said, get rid of all Ni-Cads!!! Were junk & always will be.

Geo-TH,In · Nov 22, 2013

Dewalt makes a charger that will charge all 3 types of batteries. The nice thing about this charger is it shuts off completely when batteries are charged.

mmidlam · Nov 22, 2013

A ni cad can short or develop a memory. The shorted cell can be isolated than zapped with a charged capacitor. Will re-short in a while. google ni-cad zapper.
A total discharge then recharge can erase the memory problem.
If you have several battery packs, you can combine the good cells and make a useable battery pack.

MarkB_MI · Nov 23, 2013

Ni-Cad batteries are old technology and it's best to replace your Ni-Cad tools with ones that use Ni-MH or Li-ion batteries. But there's no secret to reviving Ni-Cad batteries, plans for battery zappers have been available for decades. Like mmidlam says, they use a very large capacitor to burn out short circuits in the cell. I wouldn't recommend trying to do it with a car battery; the capacitor will send a very brief pulse of current through the Ni-Cad cell, just enough to blow the short but not enough to damage the cell.

Texasmark1 · Nov 23, 2013

Ryobi does too which I have. Costs about $30 as I recall at the big box store.

Mark

Texasmark1 · Nov 23, 2013

Or you can get a Ryobi 102 kit sometimes that has the Lithium only charger with the new battery and the price of the charger disappears in the deal.

Mark

Texasmark1 · Nov 23, 2013

I don't know about dead. The ones I was talking about was the
memory problem which kept them from taking much of a charge
and it depleting in no time when used.

After I learned of the memory problem years ago, about once a
month I would hook my Ryobi or Dewalt light to the battery and
let it run completely down then recharge it. Seemed to work for
quite awhile. Like I had my NiCads for over 10 years. But that's
all history for me. It's LI all the way.

Mark

buickanddeere · Nov 23, 2013

If a nicad has grown whiskers and shorted out . A brief blast of high voltage and high current will melt the whisker . The battery will work for a little while longer.

Jiles · Nov 23, 2013

(quoted from post at 15:48:36 11/23/13) If a nicad has grown whiskers and shorted out . A brief blast of high voltage and high current will melt the whisker . The battery will work for a little while longer.

Correct---It worked for some of mine. It has been several weeks since I did mine-- building a large outdoor deck-- and they still work.
They might not be as good as new, but they would not take any charge before I spiked them. Sure beats buying new ones again.

I have a friend that is helping me build this deck. He has a Dewalt impact driver with Ni-Cad batteries.
I bought the same driver new with Lith- Ion battery and I am pleased.
We were impressed with the light weight of the Lith-ion but not the "run" time.
My Lith-Ion batteries have a shorter run time then his Ni-Cad batteries doing the same job.
Both our chargers charge either type.

Method to revive Ni-cad 12 volt Dewalt batteries

andy r

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waltdavies

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Texasmark1

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rabbit-1

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t1

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mkirsch

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Jiles

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NYCamper62

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JMOR

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Geo-TH,In

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mmidlam

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MarkB_MI

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Texasmark1

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Texasmark1

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Texasmark1

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