Battery rejuvenate...

[Aoli]

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 ?

Steps by step please.

I have seen videos on youtube but I am looking for folks with real
experience so that I might be successful.

Thanks you.

 

[Mike]

In article <sr28gk$1j60$1@gioia.aioe.org>, Aoli <Aoli@Aoli.com> wrote:

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.

Bluntly :-

At 2 volts, and \"removed from a UPS\" they were probably already
dead (overcharging, end of life) before they were killed again by
leaving them discharged at such a ridiculously low voltage.

Your charger is a smart charger. Be smart. Take the hint.

>What can be done ?

Know anyone that needs some ballast?

I have seen videos on youtube but I am looking for folks with real
experience so that I might be successful.

Whenever I\'ve had a \"12v\" battery fail like that, it\'s dropped to
\"10v\" then \"8V\" then \"6v\" ... as one by one the cells die. They don\'t
come back. No amount of injecting distilled water, or other
popular \"remedies\" often more suited to flooded cells (including
off the wall ideas like adding various alkalis ...) do much
good.

Any fixes are low-reliability, short-duration, and not something
to rely on. Ultimately, you\'ll find the cells bulging out
of their case ... just scrap (recycle) them.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk

 

[KenW]

On Tue, 4 Jan 2022 11:51:49 -0800, Aoli <Aoli@Aoli.com> wrote:

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 ?

Steps by step please.

I have seen videos on youtube but I am looking for folks with real
experience so that I might be successful.

Thanks you.

Water ? Your kidding right ?


KenW

 

[danny burstein]

[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
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

 

[Ralph Mowery]

In article <sr2edo$ev8$1@reader1.panix.com>, dannyb@panix.com says...

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:

I let a car sit too long with out starting and the battery was \'dead\'.
Smart charger would not charge it. Hooked up a dumb charger for a while
and then the smart charger would work.

 

[Michael Trew]

On 1/4/2022 14:51, Aoli wrote:

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 ?

Steps by step please.

I have seen videos on youtube but I am looking for folks with real
experience so that I might be successful.

Thanks you.

You\'re likely SOL on those batteries.

I have an old-school heavy duty 6/12/24V car battery charger. I\'d hook
that monster up to those batteries on full blast as a last resort, and
just bake them. Don\'t over-bake, check the gauge. Worth a shot, I guess.

 

[Peter W.]

I have an old-school heavy duty 6/12/24V car battery charger. I\'d hook
that monster up to those batteries on full blast as a last resort, and
just bake them. Don\'t over-bake, check the gauge. Worth a shot, I guess.

Well, there is all that. But consider the amount of energy within any sort of lead-acid battery, even a gel-cell. With all that in mind, while \'worth a shot\', be sure to:

 

[Peter W.]

I have an old-school heavy duty 6/12/24V car battery charger. I\'d hook
that monster up to those batteries on full blast as a last resort, and
just bake them. Don\'t over-bake, check the gauge. Worth a shot, I guess.

There is that. But, consider the amount of energy in any lead-acid battery, even one as \'slow\' as a Gel-Cell. While \'worth a shot\', be sure to:

a) Do it outside. Lots of hydrogen will be released if it works at all.
b) Make sure that if anything lets loose (blows up), that the shrapnel will do no harm, or if it melts down, nothing will be damaged.
c) Have the charger on a remote switch or some such so that one does not need to be standing nearby to turn it on or off - or, stand behind something.
d) When finished with the process, give it time to cool down.
e) All the while understanding that the actual chances of this working in any meaningful way are between slim and none.

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT3kxde5kwJ5uu_GKGiM-GKFjEYFLFhvqB_fA&usqp=CAU

Peter Wieck
Melrose Park, PA

 

[ehsjr]

On 1/4/2022 3:36 PM, Mike wrote:

In article <sr28gk$1j60$1@gioia.aioe.org>, Aoli <Aoli@Aoli.com> wrote:

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.

Bluntly :-

At 2 volts, and \"removed from a UPS\" they were probably already
dead (overcharging, end of life) before they were killed again by
leaving them discharged at such a ridiculously low voltage.

Your charger is a smart charger. Be smart. Take the hint.

What can be done ?

Know anyone that needs some ballast?

I have seen videos on youtube but I am looking for folks with real
experience so that I might be successful.

Whenever I\'ve had a \"12v\" battery fail like that, it\'s dropped to
\"10v\" then \"8V\" then \"6v\" ... as one by one the cells die. They don\'t
come back. No amount of injecting distilled water, or other
popular \"remedies\" often more suited to flooded cells (including
off the wall ideas like adding various alkalis ...) do much
good.

Any fixes are low-reliability, short-duration, and not something
to rely on. Ultimately, you\'ll find the cells bulging out
of their case ... just scrap (recycle) them.

+1

 

[bob prohaska]

Aoli <Aoli@aoli.com> wrote:

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 ?

Steps by step please.

Ok, here\'s my $.02

If they need to work well, replace them.

If you just want to play, here\'s what I\'d try:

Get a dumb charger (I use a Schumacher with 2 and 6 amp ranges).

Get a tungsten filament bulb (I use an 1157 dual-filament auto taillamp
bulb) for batteries of \"normal\" size, 2-20 amp-hour. Get a voltmeter
that you trust, or can check against another similar battery.

Connect the voltmeter to the battery. Connect the negative side
of the charger to the negative battery post. Connect the positive
side of the charger to the base of the bulb. Identify the contacts
on the bottom of the bulb, selecting the small filament for little
batteries (~2 amp-hour) or the large filament for automotive-sized
batteries and connect that terminal to the positive post of the battery.
Set the charger to the upper, say 6 amp, range.

Get a sheet of notepaper, write down the time and the voltage, then
turn on the charger and record both voltage and time over the next
few hours. You\'ll have to decide how often, based on how fast the
voltage changes.

What you\'re looking for is a fairly quick (hours) ramp to about 13
volts, a slow climb (days) to 14 volts and a leveling-off at less
than 15 volts. If you see that pattern, the battery is taking a
charge. If the voltage won\'t reach 13, turn up the charger or use
the bigger filament. If the voltage goes over 15, turn down the
charger or use the smaller filament.

Once the voltage has stabilized at 14-15 volts, let it stay there
for a day, then disconnect the charger. Voltage should fall to
12.5-13.5 and stay in that range for a day. If it does, use the
bulb as a test load and repeat the voltage/time measurement. An
1157 bulb passes about half an amp on the small filament and about
2 amps on the big filament, so that gives a crude measurement of
capacity.

You might get 10% of rated capacity, most likely less.

Have fun,

bob prohaska