On May 30, 6:08*pm, gregz wrote:
SMS wrote:
In 1972, Popular Electronics had an article about how to fix NiCad
batteries that had developed an internal short and would not take a
charge. Last week I had two Dewalt battery packs (6 batteries in each)
that wouldn't charge (charger gave the fast blink error). I hauled out my
high-current power supply and zapped each cell 20 times. The packs both work fine now.

Note that you have to disassemble the battery pack to zap Ni-Cads because
you must zap each individual cell, not the entire pack at once. Also this
is not for NiMH cells or Li-Ion cells, only NiCad cells.

I never had luck at maintaing operating voltage. If you don't run down the
cells much, you might get by. They will try to go back to the shorted
condition. I would say keep them on charge, but that is another reason they
go ad. Good luck.

Greg

IMO, once you dissassemble the battery pack, what's
the point? The zapping may get you some more life,
but it's not like it;s a new set of batteries. And
considering the effort in taking apart and putting it
back together, I'd just go with new. You can buy new
batteries to replace them with on Ebay. I did that last
year with my Dewalt driver/drill. For $17 it's better
than when it was new 30 years ago.