NiCd Battery Resurrection

[elvis]

Anybody ever tried this?

Regenerating your NiCd batteries with a surge from a DC supply.

Tried it with two of my Dewalt 14.4's today. One battery (which has been completely dead for about six months) has just taken a charge and is now working (although not as new) in the gun.

The other which was still working but on it's way out seems to be giving me a good deal more torque when in the gun. Not tried them both out properly yet but it has definately been at least a partial success.

 

[Andy™]

What did you do? i have a 24V dewalt battery thats currently around 18-20V and could do with a bit help.... (since im too lazy to go on ebay and get another battery)

 

[elvis]

I hooked up 4 - 6V batteries in series and pulsed a charge through the batteries. Various theories about 'whisker' shorts across some individual cells in the batteries (hence the memory phenomenon.)

Blast 'em with a high DC voltage and it burns them off...

I used roughly this technique.

http://www.roaddevils.com/forum/showthread.php?p=57022

One of the other ones I read said you are best with a DC voltage which is twice the rating of the battery you are trying to 'ressurrect' and to hold the supply across the battery for 5 -6 secs 2 - 3 times. There is also a video online showing a guy doing it with a welding kit if you have access to one!!

http://www.instructables.com/id/Revive-Nicad-Batteries-by-Zapping-with-a-Welder/

The one above (roaddevils) seemed slightly less risky to me so I tried it first on a battery that was bound for the bin anyway and (although not great) it has definately given it some life back. It was completely deid before... fast flash on charger, not accepting charge and literally not even a turn of the gun from it! Thinkin' about given it a bit of a longer blast tommorrow to see if it gets any better...

Make sure you get the polarity correct and I read somewhere else not to charge it above 1 or 2 Volts above the rating of the battery or you can fry it.

Let me know how you get on...

 

[Andy™]

will have to try that sometime

 

[Apache]

Isn't there something about freezing them? Saw a youtube vid...........

 

[elvis]

Hmmm... can see the logic in that one as well

 

[elvis]

A guide to both:

http://ysuusy.com/easybatteryfix.html

Some of the ladies may prefer the freezing option!

 

[septiclecky]

Problem with NiCd batteries are that if they are not fully discharged before you charge them when they reach a certain voltage you think they are flat but are not. Some companies now make NiCd charges that will totally discharge the battery before it recharges them, called intelligent chargers.