Subj : Rebuilding Battery Packs
To   : Jim Holsonback
From : Elvis Hargrove
Date : Sun Oct 01 2000 02:22 am

Jim, all of them need the same thing.

They have batteries that self discharge from internal leaky/shorted
cells.  Wanna fix 'em?  Proceed as follows and get about 80-90% sucess
rate.

Get yourself a BIG capacitor. 25Kufd or bigger, fifty volts is enough
rating. (25 would do)

Fix yourself up a transformer/rectifier system, half an amp is enough,
to charg this sucker up.  Put yourself some stout test leads with probes
to zap the cells with.

Now you're gonna have to do some work to get AT the cells, because
'treating' two at once won't get it. INDIVIDUAL CELLS, thats ONE at a
TIME. You charge the capacitor, ZAP the CELL with the 25 volts or so.
(OBSERVE POLARITY!!) and after the initial CRACK it shouldn't do much.
Go on to the next cell and do IT!  Repeat as required until all cells
have been zapped.  Then charge as normal.  The total battery should come
up to nominal voltage. Any residual bad cells you have will take half to
1.2 volts off the total, and by testing individual cells with a
voltmeter you'll find the hopeless ones. Replace them with good cells
from other packs until you have as many drills and dustbusters fixed as
you need.  THEN don't leave them on the charger when you're not using
them, just charge occasionally when they start to get weak. (Prefferably
run all the way down)

Good luck and take care. Don't LEAVE them across the ZAPPER over a
second or two. I've never had one, but I'm told they could explode if
you force charged them.

 ^..^
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