'Reviving' NiCads?

[hamerhead]

I have a stack of un-rechargable batteries and have been looking into 'reviving' them. Anybody here try it?

[Dave Scepter]

23 minutes ago, hamerhead said:

I have a stack of un-rechargable batteries and have been looking into 'reviving' them. Anybody here try it?

I have with really good results however do me a favor and wear some safety goggles... 

[hamerhead]

You a pirate now, Dave?

How'd you do it?

[Dave Scepter]

7 minutes ago, hamerhead said:

You a pirate now, Dave?

How'd you do it?

Hahaha!.. no just be careful... I don't think it'll blow up, but the dead battery may have a week seam and I'd hate for some chemical to spurt out into your eyes... I can't remember exactly how I did it, it's been a couple of years... I remember something about taking a larger battery and zapping the dead battery but I can't remember the polarity, if it's + to + or + to -

I've been meaning to go back on YouTube to refresh my memory... but it does work...  

[Armitage]

Eneloop Ni-MH Pre-Charged Rechargeable Batteries are so good (or the Amazon Basics equivalent) are so good, I wouldn't even be bothered to put NiCads in anything...

[cynic]

If your charger doesn't do this, I'd spend money there first.

[hamerhead]

The charger is OK because it will still charge a couple of the packs. I have like 8 Versapak batteries that won't take a charge. Over time the insides of older cells grow arms that short things out internally. By giving them a good strong jolt, the arms burn off and they come back to life. At least that's what I've read.

Regular drill/driver packs are assembled in a way that makes cell replacement relatively easy. The Versapaks are a sealed deal that takes some finess to get apart (from the hacks I've seen). I want to try zapping them before tearing them apart.

[Dave Scepter]

Ni-cads usually first have to be "exercised then maintained" to a proper voltage but left unattended for a while, will drop to zero volts not allowing them to recharge... in this case, think "Defibulator" if you will... "CLEAR"... I also have a small solar charger " that I refurbished from a solar security light" that I use to recharge AA & AAA's... I can slowly charge alkalines as well... not back to their original 100% but good enough to use for LED lights or remote controls... 

[cynic]

24 minutes ago, hamerhead said:

The charger is OK because it will still charge a couple of the packs. I have like 8 Versapak batteries that won't take a charge. Over time the insides of older cells grow arms that short things out internally. By giving them a good strong jolt, the arms burn off and they come back to life. At least that's what I've read.

Regular drill/driver packs are assembled in a way that makes cell replacement relatively easy. The Versapaks are a sealed deal that takes some finess to get apart (from the hacks I've seen). I want to try zapping them before tearing them apart.

Ahh, battery "packs".  That changes things.  My answer was geared towards AA/AAA chargers.  The better AA/AAA "smart" chargers will refresh the batteries as needed, and typically charge in a way that better protects longevity.  

Now I'm interested in more answers as I also have a pack that got too low and is invisible to the charger.

[hamerhead]

Oops - yeah, packs. I shoulda said that in the original post. Sorry.

[Dave Scepter]

19 minutes ago, hamerhead said:

Oops - yeah, packs. I shoulda said that in the original post. Sorry.

Same thang~ packs are just single cells soldered in series... just think of turning on the garden hose with an obstruction in the middle... Might clear it?. . Might not

[veatch]

I've hit them with a short negative spark and brought them back, but they usually only last for another month or two until there is an issue -probably from the same cell. Best bet is to take it apart and find the offending cell and replace it. Sounds like that might not be an option on in this case, though...