I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if
they are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely
discharged and that there are a bunch of shorted out cells in the set.
Cells were low on water, topped them off with distilled water. I think I
will take a regulated DC power supply, see what voltage it starts to
take current. From my reading, a functioning but fully discharged cell
should start taking current at 1.98 volt and fully charged at 2.10 volt.
So a 6 volt battery with one shorted cell should start at around 4 volts
then go up to 4.2 volts at full charge. Any other suggestions on how to
test, deal, whatever?

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

On Tue, 19 May 2009 09:11:01 -0500, RoyJ
wrote:

I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if
they are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely
discharged and that there are a bunch of shorted out cells in the set.
Cells were low on water, topped them off with distilled water. I think I
will take a regulated DC power supply, see what voltage it starts to
take current. From my reading, a functioning but fully discharged cell
should start taking current at 1.98 volt and fully charged at 2.10 volt.
So a 6 volt battery with one shorted cell should start at around 4 volts
then go up to 4.2 volts at full charge. Any other suggestions on how to
test, deal, whatever?

A really flat deepcycle battery can exhibit considerably less than
1.98 volts per cell. Sometimes it takes a pretty healthy shot of
current to "get their attention".

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

To test: just measure the voltage on each battery. Those that are
more than 1.5 volts or so (per cell) are probably OK. Those that are
lower than that may still be OK, maybe not.

To keep alive: charge with a good charger, keep on trickle charge by
a good charger. The worst thing you can do to a battery is overcharge
it but a good charger won't do that.

On Tue, 19 May 2009 09:11:01 -0500, RoyJ
wrote:

I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if
they are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely
discharged and that there are a bunch of shorted out cells in the set.
Cells were low on water, topped them off with distilled water. I think I
will take a regulated DC power supply, see what voltage it starts to
take current. From my reading, a functioning but fully discharged cell
should start taking current at 1.98 volt and fully charged at 2.10 volt.
So a 6 volt battery with one shorted cell should start at around 4 volts
then go up to 4.2 volts at full charge. Any other suggestions on how to
test, deal, whatever?

Here's a really good article
http://www.windsun.com/Batteries/Battery_FAQ.htm. I think you'll want
to fully charge, test SG, and probably then equalize, perhaps multiple
times. Odds of anything close to full capacity recovery probably
aren't great.

"Flooded battery life can be extended if an equalizing charge is
applied every 10 to 40 days. This is a charge that is about 10% higher
than normal full charge voltage, and is applied for about 2 to 16
hours. This makes sure that all the cells are equally charged, and the
gas bubbles mix the electrolyte. If the liquid in standard wet cells
is not mixed, the electrolyte becomes "stratified". You can have very
strong solution at the top, and very weak at the bottom of the cell.
With stratification, you can test a battery with a hydrometer and get
readings that are quite a ways off. If you cannot equalize for some
reason, you should let the battery sit for at least 24 hours and then
use the hydrometer. AGM and gelled should be equalized 2-4 times a
year at most - check the manufacturers recommendations, especially on
gelled."

I'll add - the equalization process will hopefully blast off some the
scaling that's inevitably formed.

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

Are you sure they're not AGM? Regardless, I'd contact the maker for
some specific advice. They may need equalizing as well, but you have
to be very careful doing it.

Wayne

IMO, any type of LA lead/acid battery that's neglected for years is
unrecoverable. The plate surfaces are likely to start to become sulfated as
soon as a battery is left at a low voltage level/dead.
From what I've read, LA batteries with liquid electrolyte can sometimes be
desulfated, but batteries with gel electrolyte can not.

Desulfating consists of high frequency (10 kHz, maybe higher) current pulses
that are said to remove the sulfated coating, which is then held in
suspension, or removed by replacing the liquid electrolyte.

If the batteries were left in a low state/dead for only weeks (or possibly a
month), but wouldn't take a charge, there is a variac and rectifier
improvised technique that often works to get a LA batterys' condition to a
point where it can be properly charged.

If some liquid electrolyte batteries were an exceptionally high grade of
batteries, they may be recoverable by desulfating if they had been left at a
low voltage level/dead for a couple of months, but I highly doubt that any
that have been completely dead in excess of 6 months would be recoverable.

There is a lot of battery info online, some of it factual and some related
to fluke situations. Fluke being a battery that was assumed to be fully
recovered, performs badly within a short time, like the car battery that
starts the engine fine, but suddenly won't on a cold day.
The serious non-professional battery users are the folks that live
off-the-grid. These folks strive to use and maintain batteries as
effectively as possible.

I'm not aware of any quick, easy evaluation methods that will accurately
indicate a battery's watt-hour capacity or potential reliability, unless the
battery is in very good condition, and properly maintained.
I suspect that when a LA battery (and most other types) has been left in
dead condition for any amount of time, it's performance capability and
reliability are greatly diminished.

What Wayne suggests about being careful is wise. Many improvised/hack
methods aren't particularly safe, and many methods probably shouldn't be
left unattended.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"RoyJ" wrote in message
news
I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if they
are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely discharged
and that there are a bunch of shorted out cells in the set. Cells were low
on water, topped them off with distilled water. I think I will take a
regulated DC power supply, see what voltage it starts to take current.
From my reading, a functioning but fully discharged cell should start
taking current at 1.98 volt and fully charged at 2.10 volt. So a 6 volt
battery with one shorted cell should start at around 4 volts then go up to
4.2 volts at full charge. Any other suggestions on how to test, deal,
whatever?

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

On Tue, 19 May 2009 09:11:01 -0500, RoyJ
wrote:

I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if
they are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely
discharged and that there are a bunch of shorted out cells in the set.
Cells were low on water, topped them off with distilled water. I think I
will take a regulated DC power supply, see what voltage it starts to
take current. From my reading, a functioning but fully discharged cell
should start taking current at 1.98 volt and fully charged at 2.10 volt.
So a 6 volt battery with one shorted cell should start at around 4 volts
then go up to 4.2 volts at full charge. Any other suggestions on how to
test, deal, whatever?

Use a 12 Volt charger, charge in pairs. May need to sit on charge for
hours or even days before they begin to charge. Totally dead there is
no acid, only water. Water does not conduct electricity well, so as
the hours pass and the water slowly becomes acid the batteries will
start to charge. After charge check for full voltage. then add a
load like a headlight bulb and see if they can hold voltage with a
load on them. If they go from 12.6 - 13 volts to around 10 quickly
then there is a dead cell somewhere in there.

All above is with the batts in pairs because 12 volt loads and
chargers are much more common and what I use.

If you use a DC supply make sure it is current limited to 5 or 10 amps
max if you leave it on without constant supervision, when they do
decide to start charging current can go up high.

A single 6V batt with a dead cell just might read 6V+ with a meter,
the dead cell will show itself when a load is applied. A 6V+ reading
is very likely when checked fresh off a charger.


Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

Above but with each battery separate from the rest.

Thank You,
Randy

Remove 333 from email address to reply.

"RoyJ" wrote in message
news
I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if they
are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely discharged
and that there are a bunch of shorted out cells in the set. Cells were low
on water, topped them off with distilled water. I think I will take a
regulated DC power supply, see what voltage it starts to take current.
From my reading, a functioning but fully discharged cell should start
taking current at 1.98 volt and fully charged at 2.10 volt. So a 6 volt
battery with one shorted cell should start at around 4 volts then go up to
4.2 volts at full charge. Any other suggestions on how to test, deal,
whatever?

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

You have received a lot of good information and the only thing I can add is
to be sure to watch the electrolyte level carefully. If the batteries start
to take a charge and/or warm up, the level can rise quite a bit and this can
result in overflow. It is best to start with the level just at the top of
the plates.

Don Young

RoyJ writes:

This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

Check the date codes on the SLA batteries. With proper maintenance they
only last 5-8 years. Much less if abused. After that they're a recycling
nuisance.

On Tue, 19 May 2009 21:10:17 -0500, "Don Young"
wrote:


"RoyJ" wrote in message
news
I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if they
are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely discharged
and that there are a bunch of shorted out cells in the set. Cells were low
on water, topped them off with distilled water. I think I will take a
regulated DC power supply, see what voltage it starts to take current.
From my reading, a functioning but fully discharged cell should start
taking current at 1.98 volt and fully charged at 2.10 volt. So a 6 volt
battery with one shorted cell should start at around 4 volts then go up to
4.2 volts at full charge. Any other suggestions on how to test, deal,
whatever?

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??

You have received a lot of good information and the only thing I can add is
to be sure to watch the electrolyte level carefully. If the batteries start
to take a charge and/or warm up, the level can rise quite a bit and this can
result in overflow. It is best to start with the level just at the top of
the plates.

Don Young



Survival of the 6V batteries after 4 years uncharged is
pretty unlikely. They are likely to be deeply sulphated and
refuse to accept a charge at anything like the usual max of
2.5v/cell. Less severe cases can sometimes be partially rescued
by prolonged low current overvoltage charging until it starts to
accept charge at less than 2.5V/cell but the results are seldom
worth the hassle.

Chances are much better with the gel pack batteries.
Dependent on local ambient temperature these happily hold their
charge for a year or more and just need a freshening charge
before putting into service. In normal use as backup batteries on
permanent float charge they seem to last about 5 years but many
organisation routinely replace them at 3 years or less. Stored,
charged, at reasonably low temperatures the life can be very long
indeeed. I keep a few 12v Yuasa batteries in a domestic fridge
when I am not using them. These were rescued after their 3 year
float charge stint and and are still going strong after nearly 10
years.

Yuasa recommendation for freshening charge after long
storage is either 10 hours constant current at 0.1C or 24 hours
constant voltage at 2.4V/cell

Jim

Had a go at the 6 volt cells this afternoon. Put two of them in series
so I could use a 12 volt charger. Started with a voltage of 1.4 volts.
Put a small charger on the 50 amp boost setting with a Fluke DVM to
monitor actual voltage at the terminal, it started at 11.4 volts and 4
amps. Voltage gradually crept up to 13.8 volts with no change in
amperage after an hour. Every few minutes I'd turn off the charger, see
what the battery would do. First time it went to about 8 volts and
dropped rapidly. Each time it would stabilize at a higher voltage and
drop off more slowly. After an hour or so it would start at 11.8 volts
and drop off to about 8 volts after a minute or so.

I also found some more data on the machine. I'd guess at a 1997 +/- 2
years mfg date, last time anyone dealt with it was 2001. An olde.

So...... sounds like it is not shorted but is highly sulphated. Could
possibly be brought back to life but not to full strength. And bringing
it back would take a bit of fussing, especially since I'd need to do it
3 times for the full set of 6 batteries. I do have a big industrial
strength charger but it is polarity protected, needs to read the battery
voltage to assure it has the polarity correct. This whole thing sounds
fairly marginal unless I have a project that is "shovel ready" ( I don't)

I also dug into the control package: 2 boards: a signal board and a
power control board. Power control board looked like massive parallel
(dozen chips) FET in an 'H' bridge configuration.

RoyJ wrote:
I've got a couple of battery packs in the storeroom that need some
attention. Both have been stored for periods of time, need to see if
they are usable or get them out to the scrap dealer.

Pack #1 is a set of 6 deep discharge 6 volt batteries in a mobile cart.
Charger for it was trash, had fried circuit board. Unit has been sitting
for multiple (4+??)years. I'm betting that they are completely
discharged and that there are a bunch of shorted out cells in the set.
Cells were low on water, topped them off with distilled water. I think I
will take a regulated DC power supply, see what voltage it starts to
take current. From my reading, a functioning but fully discharged cell
should start taking current at 1.98 volt and fully charged at 2.10 volt.
So a 6 volt battery with one shorted cell should start at around 4 volts
then go up to 4.2 volts at full charge. Any other suggestions on how to
test, deal, whatever?

Pack #2 is actually 3 packs of 19 each 12 volt gel pack batteries (228
volts per pack, there may be a couple batteries missing). It came from a
huge battery backup for a computer center. I suspect it was set up to
provide 3 phase 208 power. This bunch has been sitting for about a year
with no attention. These are gel pack (??), about the same size as a
standard auto battery, fully sealed, and sit on their sides. How do I
test? What should I do to keep them alive and well for future projects??