recharging dead ni-cad batteries

Anyone ever seen or heard of this being done with a welder? My kid works in a body shop and says his co-workers did it one day and it worked!


http://www.youtube.com/watch?v=PzIlVLOH9XI

I've heard you can reverse charge the battery using a 9V disposable battery to "deplaque" the old NiCad and that will allow it to take a charge again. That's the same thing the welder is replicating.

Interesting...but I can easily see the battery pack exploding when doing something like this

My supervisor at work saw this video and a couple of others on youtube. We kept the 110 welder as is...gun is positive, ground is negative. Wire speed as low as it will go, voltage all the way up. Zapped it a few times and sure enough, the batteries went up. He took the batteries home and charged them and all is well! Both Makita batteries were dead. Wish I had seen this video a couple of months ago as I just threw away two batteries and the replacements were 80 bucks a pop.

Never done it, but I found this if anyone wants a hardcopy.

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

Having been involved with R/C racing for many years, I've dealt with a LOT of Ni-Cad battery packs. I have 'zapped' a few cells (individual sub C sized) with a 12 volt car battery (reverse polarity) occaisionally and they do come back somewhat.
Unfortunately, they don't seem to have the same 'punch' they did before and the pack they are built back into won't last as long as the original normall would.