On Sat, 12 Dec 2009 15:45:25 -0800 (PST), infiniteMPG
wrote:
I have a great Black & Decker 24VDC FireStorm Hammer Drill that works
GREAT. The problem I am having is within the first few months, one
battery wouldn't hold a charge. So I got a spare but now I have a
second one not holding charge. Looked online and since this isn't the
latest and greatest thing now, the batteries are EXPENSIVE!
FireStorm FS240BX Battery Pack
I am not about to pay as much for a new battery as I can buy a new
drill for, so my question is : IS THERE ANY WAY TO REVIVE A
RECHARGEABLE BATTERY????
I got fed up with the NiCd and NiMH battery game long ago. Some of my
portable hand tools are now running off lead acid gel cell batteries.
In obtained a pile of 12V 7A gel cells which have kept various UPS's
running. I try to buy 12V and 24V power tools, so that they'll run
directly off the battery. I use about 6ft of #12 or #14 wire to the
battery. Charging is with a home made gel cell charger, that I have
set for long battery life to not go above about 85-90% of charge. It's
actually easier to kill a gel cell than a NiCd or NiMH pack, so the
charger is critical.
Oddly, I've found that using the tool without the battery pack reduces
the weight sufficiently to make it easier to use the power tools.
However, the balance on a drill is all wrong, with the drill appearing
top heavy and awkward.
I've also been doing some very disorganized experiments with a West
Mtn Radio CBA-II battery tester:
http://www.westmountainradio.com/CBA.htm
I do not have the professional software, so I can't do cyclic battery
life testing. However, I have noticed an oddity comparing no-name and
quality NiMH cells. The initial charge point for the quality cells is
at about 90% of full charge, while the cheap no-name cells are closer
to 100%. This is sorta an artifact of the way the CBA-II works. It
does not charge the battery packs. It just discharges them, and
graphs the discharge curve. The stored power (energy?) is the area
under the curve. When I charged a pack using the supplied charger, I
saw the differences in initial charge. When I used my home made
charger, I could not tell the difference between quality and junk
cells on the initial few runs.
Therefore, my guess(tm) is that you can make your B&D 24VDC Fire
Belching Drill battery packs last much longer if you use a different
and more conservative battery charger that stops charging well before
hitting 100%. Incidentally, the easy way to tell if you're
overcharging a NiCd or NiMH battery pack is that if they get hot or
even warm, you're overcharging or charging too fast.
This should offer a clue on NiCd and NiMH charging:
http://www.angelfire.com/electronic/hayles/charge1.html
Note that not all cells can be quick charged.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558