[snip]
>>Battery rejuvenate
>>
>>I have several 12V Gel cell batteries that came out of UPS units.
>>
>>They all test at around 2 Volts.
>>
>>I removed the cell caps and added distilled water.
>>
>>My charger refuses to try to charge.
>>
>>What can be done ?
>>What charger might be needed ?
If, and that's a pretty big and unlikely if, the
batteries can be restored to anything useful, you've
got to try charging them up first.
Yeah, you hooked up a charger, but many of them
are "smart units" that analyze the load (the battery)'s
electrical characteristics to determine how much
current to send across.
Since your batteries are dead, dead, dead (so to speak)
with only 2 volts (probably less..), the chargers
refuse to send any current across.
So... you've got to set up a "dumb" charger.
If you don't have one around, there are two
simple ways to try:
a: find an old phone or similar wall wart charging
block rated at 12V DC . Attach the wires to
the battery and leave it on for ten hours.
Then measure again and try the smart charger.
b: use jumper cables from a known _good_ and _charged_
battery to feed the dead one. Then measure again, etc.
I've done this exact same procedure with, yes,
dead UPS units.
In about 1/2 of the batteries I've been able to
get them back up to some useful level of charge.
Note by "useful" I mean a fraction of the original,
as I'm using these UPS'es for:
1: to filter out the 1/2 second glitches that
would otherwise reset my tv and cable modem, requiring
fifteen minutes (GRUMBLE!!) to come back up [a],
2: to give enough time to shut down whatever
they're hooked to.
Every so often I get one that does, indeed, get
close enough to original spec...
[a] plenty of those when, for example, a grid
area 15 miles away goes dark or is turned
back on...
--
_____________________________________________________
Knowledge may be power, but communications is the key
dan...@panix.com
[to foil spammers, my address has been double rot-13 encoded]