Best method to revive NiCd drill batteries?

[SamValiant]

I have a few DeWalt and Atlas Copco NiCD drill batteries that have given up the ghost. I've read that giving them a high voltage DC for half a second x 10 does a pretty good job of reviving. Some use welders, some use other batteries.

Which methods have people tried and been successful with?

They are 1.3 and 2.4ah 14.4v batteries. Can I use my big battery (12v Deep Cycle 120ah 1300cca?) for this purpose?

Cheers,
Sam

[Mike Harrison]

This is only the case where batteries have internally shorted, and show zero volts even under
charge.
If the cell reads any voltage (>0.5v) across it, this isn't the probem and is probably terminally
dead.
I believe this is caused by internal metallic dendrite growth, and can sometimes be recovered by
passing a brief current to melt the dendrite like a fuse. Discharging a large capacitor (a few
thousand uf) is safer than connecting it to a big battery as it limits the total energy delivered.

This should only be done on a cell-by-cell basis, not on a whole series pack.