# Resurrecting lame NiCD's by voltage surging



## speedster1 (May 13, 2009)

While talking to a fellow the other day about power tools we got the the topic of lame batteries. I was complaining that my old 12V Milwaukee drill had two batteries that would no longer hold a charge. And that replacement batteries were going to cost me more than a new drill. He suggested I voltage surge the batteries. I had never heard of the term but he gave me detailed instructions on how to do it. Basically the NiCD cells have crystals that develop in them over the years that need to be broken down in order for the battery to hold a charge. After googling this method I appears to be a widely accepted practice. 

So I couldn't resist trying it and felt i had nothing to lose. I am a DIY'r after all  I wore some eye protection and used lantern batteries wired in series. Before voltage surging the 12V packs read 6.5V and 5.8V on fresh charges. After voltage surging I charged the packs and they read 13.8V and 13.7V respectively. They both seem to work like new. 

Now I'm wondering, if any of you have tried this method what type of success have you had? I'm wondering how long I can expect this fix to work. The fellow I got the info from said he's had fixed packs in operation for a couple of years and that this procedure can be redone several times before losing it's effectiveness. 

Seems like a good way to get a few more years out of your old tools. Gonna try this method on a shark handheld vacuum that also uses NiCDs. Along with a 14.4 volt craftman drill/saw combo that my dad pawned off on me.


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## liquidvw (Jun 8, 2009)

while I haven't tried this, I have read some articles on the subject. I too, wonder how long you can expect this fix to last.


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## Yoyizit (Jul 11, 2008)

Actually it's a current surge that vaporizes the conductive whiskers that form over time. 
A charged capacitor is the best way to dump energy into these filaments and there is at least one tried and true circuit in Cyberspace.


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## Durt Ferguson (Apr 14, 2010)

I've been tempted to try this with my arc welder, however self preservation, and being accident prone have stopped me. Just afraid it will explode.


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## speedster1 (May 13, 2009)

Durt Ferguson said:


> I've been tempted to try this with my arc welder, however self preservation, and being accident prone have stopped me. Just afraid it will explode.


I suppose an arc welder would be a great way to accomplish this but I too have a healthy fear of electric shock. I don't have an arc welder anyway. 

DC voltage is DC voltage but for some reason I feel more safe with lantern batteries than I do a welder. lol

If you have any spent batteries that are lower voltage < 12V you can actually use the functioning battery of a more powerful drill like 18V or 24V to use as a power source.

The batteries I fixed are still working fine. Used my Milwaukee quite a lot last night and seems to function as new.


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## Yoyizit (Jul 11, 2008)

The voltage of your rejuvenator should be less than 1.4 vdc per Nicad cell. Nominal Nicad cell voltage is 1.2 vdc.


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## 57_Hemi (Jul 28, 2010)

I tried this approx 2 years back. I have a 15.6v METABO cordless hammer drill and 1 battery would no longer hold any charge. Probably b/c it sat in my garage for almost 2 years (COLD TORONTO WINTERS) while the drill and my other battery were all cozy in thier original case inside the house.

Used a spare 18v DeWalt battery I had (fully charged) and....... PRESTO !!!!! 

My dead METABO 15.6v battery came to life and has been working fine ever since.


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## Yoyizit (Jul 11, 2008)

57_Hemi said:


> 15.6v battery


So it's 13 cells.


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## 57_Hemi (Jul 28, 2010)

Yoyizit said:


> So it's 13 cells.


I assume it would be a 13 cell battery. I do know that the batties for my Metabo are 2.4Ah which apparentley offer more power than the standard 1.5Ah batteries. I've used it mainly for cliping conduit runs and drilling thru block, concrete & brick for alot of satalite, telephone and cable installs over the years.

Regardless...... I know one thing, I've had that drill for over 8 years now and it's bulletproof. The only one complaint I have is the actual weight of the drill. It's a bit of a "pig"....lol But I dont mind. I see original OEM batteries (non refurbished) still going for $100-$115 each.

Also, all internal components in the drill are german made.....(I dont think u can go wrong with that) 

I'd recommend it to anyone....... METABO gets a :thumbup:

cheers !


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## Yoyizit (Jul 11, 2008)

57_Hemi said:


> I do know that the batties for my Metabo are 2.4Ah which apparentley offer more power than the standard 1.5Ah batteries.


Yes, ideally 2.4 offers 1.6x the watthours of energy than the 1.5.


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## hyunelan2 (Aug 14, 2007)

Perhaps I should try this on my old Craftsman drill. I've long since bought a new drill, but have the old drill with one battery that's dead, and another that doesn't last long. It would just be handy to have a second usable drill.

What are you using to move the current into the dead battery, jumper cables?


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## ratherbefishin' (Jun 16, 2007)

Looks like time to post this link again: http://ysuusy.com/easybatteryfix.html

Still haven't tried it yet myself, but hearing that it's worked for others puts it near the top of my list for this weekend. Got a couple 18v I was getting ready to rebuild, but now I figure I might as well give this a try first. I'll run my boat batteries in series for 24v, and if that doesn't work I'll add a car battery and pop 'em with 36v. I'll let you guys know how it goes.


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## speedster1 (May 13, 2009)

hyunelan2 said:


> Perhaps I should try this on my old Craftsman drill. I've long since bought a new drill, but have the old drill with one battery that's dead, and another that doesn't last long. It would just be handy to have a second usable drill.
> 
> What are you using to move the current into the dead battery, jumper cables?


I just used 12/2 romex. Held the negative on and tapped the hot wire to the hot terminal quickly.

I wonder if you could do this with 2 or 3 9V batteries wired in series?


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## Yoyizit (Jul 11, 2008)

speedster1 said:


> I wonder if you could do this with 2 or 3 9V batteries wired in series?


I'd do them one at a time.


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## speedster1 (May 13, 2009)

I did this again this morning on my bro-in-laws 18V dewalt and it seemed to work well. I don't think he believed me when I told him we could fix the pack but I think I've changed his mind.


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## ratherbefishin' (Jun 16, 2007)

Finally got around to trying this on a couple old 18v 1.4Ah Hitachi batteries that wouldn't take a charge and I gotta say I'm a pleasantly surprised skeptic.
First charge after zapping didn't hold long, but the second seems to be fine. One went to 21.6v, the other to 21.7. Used one in a flashlight last night for about 30 minutes and the charge held, still well above 18v. I shoulda taken this seriously years ago:whistling2: 
I used two 12v marine batteries in series and only needed to zap them once to get results.
I'm still not convinced yet how long this fix will last, but even if it's only a few months it's worth a shot. After all, it's a free fix:thumbup:


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## speedster1 (May 13, 2009)

ratherbefishin' said:


> Finally got around to trying this on a couple old 18v 1.4Ah Hitachi batteries that wouldn't take a charge and I gotta say I'm a pleasantly surprised skeptic.
> First charge after zapping didn't hold long, but the second seems to be fine. One went to 21.6v, the other to 21.7. Used one in a flashlight last night for about 30 minutes and the charge held, still well above 18v. I shoulda taken this seriously years ago:whistling2:
> I used two 12v marine batteries in series and only needed to zap them once to get results.
> I'm still not convinced yet how long this fix will last, but even if it's only a few months it's worth a shot. After all, it's a free fix:thumbup:


Yes I don't expect them to be as good as brand new batteries but this method certainly works pretty well. I've been using my old batteries pretty extensively since doing this and they seem to be holding up pretty well.


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