"restore" nickel cadmium batteries?


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Old 03-07-11, 01:41 PM
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"restore" nickel cadmium batteries?

Is there a very reliable method of successfully "restoring" the batteries within the nickel cadmium battery packs of cordless power tools. I've got a few drills and flashlights that use the snap-in battery packs but they barely charge up any more in the charger. Seems like I read you can bring them back to life somehow with various methods, like taking them apart and then "zapping" them with a car battery. If anyone could briefly explain the specific steps and/or would care to comment/advise otherwise about this, it would be appreciated.
 
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Old 03-07-11, 02:23 PM
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It would be a complete waste of time to try back magic on worn out batteries.
In use they degrade and if you have had a reasonable life out of them no freezing, zapping or otherwise will bring them back from the dead.

Some have reported good success with companies that rebuild them by installing new ni-cad cells into your old cases.
IMO however you would need to have a very expensive tool or have an emotional attachment to them to make rebuilding them worthwhile.

You can often get a good drill on sale for as much as replacement batteries.
 
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Old 03-07-11, 02:49 PM
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I read a how to article awhile back about zapping old tool batteries back to life. The biggest thing is figuring out which contacts are hot and which one is ground. I had a 19.2 volt battery pack that would no longer take a charge so figuring I had nothing to loose, I zapped it with 12 volt from my car battery charger and then plugged it into the 19.2 battery charger. Surprisingly the battery pack took a charge and still holds a charge for a short while. That was about a yr ago and I still use that battery pack some. It doesn't hold a charge for as long as the new replacement does and does tend to loose it's charge over night. I don't know if there are any dangers involved with zapping a battery with a higher voltage.

I looked into having the batteries refurbished but the cost is prohibitive and never did find a source for the correct batteries to attempt a rebuild myself. Over all - buying a new replacement battery pack seems to be the best deal.
 
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Old 03-07-11, 03:34 PM
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Okay. Thanks you guys. I don't feel like messing around with it if its not worth it in the long run. I'll consider just getting (buying) some replacement battery packs instead. Or just replacing the old tools altogether if as mentioned they go on sale for reasonable price for not much more than new battery packs.
 
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Old 03-07-11, 03:40 PM
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Depending on the technology a battery charger may not charge the pack if the voltage is out of range. This is often the case with lithium packs if you use the tool too long and the voltage drops below the set point, making the charger think the pack is bad. Using a manual charger or zapping just enough to get the voltage back up in the acceptable range makes the charger think the pack is OK to charge.
 
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Old 03-07-11, 03:46 PM
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Originally Posted by Pilot Dane View Post
Depending on the technology a battery charger may not charge the pack if the voltage is out of range. This is often the case with lithium packs if you use the tool too long and the voltage drops below the set point, making the charger think the pack is bad. Using a manual charger or zapping just enough to get the voltage back up in the acceptable range makes the charger think the pack is OK to charge.
Hmm. Then maybe I should try to use a manual charger or the zap method. Back to square one here with my question.
 
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Old 03-08-11, 10:11 AM
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I've had this link for over a year but I have never tried any of the tricks. Use them at your own risk.

http://ysuusy.com/easybatteryfix.html
 
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Old 03-08-11, 03:06 PM
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Exclamation

I looked at that link and saw the suggestion to connect a 12 volt battery to as low as a 1.5 volt battery!
There could be a glimmer of truth to what the article suggests but it is somewhat irresponsible to not take into account average folks ability to sort out really bad info.
A 1 1/2 volt battery that was in bad condition could easily explode if the charging battery was in good condition.

My suggestion is to not count on a miracle and just pony up and buy new batteries.
 
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Old 03-08-11, 03:31 PM
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Yeah I think just pony up like you suggest. With my luck the whole business will blow up in my face or something. Besides the safety factor, just seems too much hassle for what seems like the results are rather questionable for the trouble.

Thanks all for the replies/input.
 
 

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