Resurrecting lame NiCD's by voltage surging

speedster1

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.

liquidvw

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.

Yoyizit

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.

Durt Ferguson

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.

speedster1

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.

Yoyizit

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

57_Hemi

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.

Yoyizit

So it's 13 cells.

57_Hemi

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

cheers !

Yoyizit

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

hyunelan2

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?

ratherbefishin'

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.

speedster1

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?

Yoyizit

I'd do them one at a time.

speedster1

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.