On May 25, 4:14 pm, Larry wrote:
tlindly wrote in news:1180095084.932902.130030
@z28g2000prd.googlegroups.com:

[note: permanent damage if you go
below 10.5V]

It arrived at ZERO! You're absolutely right....this puppy is TOAST! Why
try to charge a "PERMANENTLY DAMAGED" AGM battery?

Just to prove it to yourself


SEND IT BACK!

Yep, that's easier...


Larry
--
Grade School Physics Factoid:
A building cannot freefall into its own footprint without
skilled demolition.

after 18 hours if charging they are at 12,54 volts,

any thoughts ?

* navti wrote, On 5/27/2007 8:20 AM:
after 18 hours if charging they are at 12,54 volts,

any thoughts ?


Voltage is almost meaningless. That seems a tad low, but it depends
on a number of subtle factors. Also, what was the charge rate? You
mentioned trickle charging, so they might not be fulling charged yet.

You need to charge them with a proper charger, then do some sort of
load test - that's the only thing you can do to determine the health.
Someone suggested a high intensity lamp, you could also use an
inverter with a heating appliance. Or you could take them to a
friendly battery shop or garage that might have a proper load tester.

"navti" wrote in message
ps.com...
after 18 hours if charging they are at 12,54 volts,

any thoughts ?


Sounds like things are looking up. I'd try to get ahold of a good
battery charger of the three-stage variety and put a good float charge
on them (the last stage). Then do a load test to check capacity. You
just might be OK in spite of what all the ignorant,
self-appointed-expert naysayer's ranting raving. I hope it works out for
you. If so please keep in touch and let us know so the know-it-alls can
get slapped around a little bit more...

Wilbur Hubbard

On May 27, 9:20 am, navti wrote:
after 18 hours if charging they are at 12,54 volts,

any thoughts ?

Do you have any idea at what rate you are charging? I don't remember
you mentioning if your charger puts out 2 amps or 10 or 20 or what.
Did you take this voltage measurement with the charger connected and
charging? Or had you disconnected the charger first? Did you put a
small load on the battery for a short time after charging to take off
the surface charge before testing the voltage?

On May 28, 11:52 pm, "Ken Heaton, Cape Breton Island, Nova Scotia"
wrote:
On May 27, 9:20 am, navti wrote:

after 18 hours if charging they are at 12,54 volts,

any thoughts ?

Do you have any idea at what rate you are charging? I don't remember
you mentioning if your charger puts out 2 amps or 10 or 20 or what.
Did you take this voltage measurement with the charger connected and
charging? Or had you disconnected the charger first? Did you put a
small load on the battery for a short time after charging to take off
the surface charge before testing the voltage?

I think I was charging at 7 or 8 amps. I am going to do some more
charging today. My charger can put out 10 or 20 amps.
I charged at 10 but had other loads on the generator (yes i charged
with a generator because thats how i will be using them).
I took the reading after 24 hours of settling,
THats a very good tip regarding the surface charge,
I will try that after my next charge,

On May 27, 12:20 pm, navti wrote:
after 18 hours if charging they are at 12,54 volts,

any thoughts ?

Is that;
1] 12,54 volts with charger still attached and charging?
2] 12,54 volts with the battery connected to nothing but a digital
Volt meter?
3] 12,54 volts with the battery now "running" 3-15 amps [whatever
your normal boat's usage is]?

If 1, you definitely have a bad cell [or your charger is broken].
Should be 13.6-14.4 [14.4 at the start {batt. dead} to 13.6 trickle
charging the fully charged batt.] unless you have a 'smart charger' or
reconditioner
If 2, This is totally meaningless data, all that most people ever know
of batteries, and how battery salesmen make their fortunes...[this is
"surface charge" you might have heard of...]. In a liquid battery,
this should stay at 13.6 for quite some time after removing the
charger [AGM's, with their inherently defective chemical nature
pointed out so eloquently by {I believe} Larry earlier, will usually
show something less depending {I reckon} on their quality], But even a
battery with a known dead cell can show this phantom voltage, so pay
it no heed!!!
If 3, looks promising. You still have to do the discharge test [run
10 amps for 11 hours, or 2 amps for 55 hours] to know if 110aH battery
is "good"

On May 29, 8:38 am, tlindly wrote:
On May 27, 12:20 pm, navti wrote:

after 18 hours if charging they are at 12,54 volts,

any thoughts ?

Is that;
1] 12,54 volts with charger still attached and charging?
2] 12,54 volts with the battery connected to nothing but a digital
Volt meter?
3] 12,54 volts with the battery now "running" 3-15 amps [whatever
your normal boat's usage is]?

If 1, you definitely have a bad cell [or your charger is broken].
Should be 13.6-14.4 [14.4 at the start {batt. dead} to 13.6 trickle
charging the fully charged batt.] unless you have a 'smart charger' or
reconditioner
If 2, This is totally meaningless data, all that most people ever know
of batteries, and how battery salesmen make their fortunes...[this is
"surface charge" you might have heard of...]. In a liquid battery,
this should stay at 13.6 for quite some time after removing the
charger [AGM's, with their inherently defective chemical nature
pointed out so eloquently by {I believe} Larry earlier, will usually
show something less depending {I reckon} on their quality], But even a
battery with a known dead cell can show this phantom voltage, so pay
it no heed!!!
If 3, looks promising. You still have to do the discharge test [run
10 amps for 11 hours, or 2 amps for 55 hours] to know if 110aH battery
is "good"

2 at present. I will try 3 and get back to you,.
ps
its not a boat its a camper-van

navti wrote in news:1180442689.967642.246260
@p47g2000hsd.googlegroups.com:

its not a boat its a camper-van



GEEZ, don't tell 'em that! They think yachts are more special than mere
RVs...(c;

One waterfront property owner called the marina "That Floating Trailer
Park" and got 'em all excited in Beaufort, SC....(c;

Larry
--
Grade School Physics Factoid:
A building cannot freefall into its own footprint without
skilled demolition.

tlindly wrote in news:1180424314.345874.99050
@i38g2000prf.googlegroups.com:

show something less depending {I reckon} on their quality]

I love the "quality" hype. One plate is lead. One plate is lead
dioxide. The electrolyte is gauze soaked with a dilute solution of
H2SO4. The quality is in the label and plastic case.

Torn apart, and I have torn them apart, I don't see any quality inside.
You gotta go to a "quality" battery factory to believe it. Exide makes
"quality" batteries. Their plant was in Sumter, SC. It wasn't like a
laboratory, I can tell you. It's a dirty, nasty, smelly business making
batteries. You wouldn't wanna work there....(c; None of them are made
in a laboratory just for you.

A lead-acid battery "should stay at 13.6 for quite some time" is true. A
long time as it's dependent on chemistry. But, because they all are
built as cheaply as is humanly possible, no matter how good the quality
on the label is, they have impurities, notably iron, in them that self
discharge and eat areas of the plates. This doesn't harm the plates, but
consumes, irrecoverably, the acid...which is what makes a battery go
"dead". This happens to "new" batteries in the first 6 months, until the
impurities have been eaten away. Every month for the first 6 months, the
specific gravity of each cell should be measured, tracked and adjusted
back, after the battery has been fully, SLOWLY recharged, to 1.270
specific gravity, replacing the acid "local action" has eaten away.

Back in the diesel submarine days, Charleston Naval Shipyard had a
massive battery shop to restore and rebuild the boats' 6,250AH lead-acid
cells, that were about as tall as a man and 5' x 4' dimensions. The
batteries were made to drain, cut open and remove the plates/separator
structure, clean out and replace the core structure. It was something to
witness close up. The acid was purified and recycled, not dumped in the
river as some thought. They had a chemical plant to do just that. Once
rebuilt, the batteries were carefully fueled with purified acid, left to
"perk" a week, then taken to a massive gallery that was the shipyard's
battery charger room to be cycled and tested. The battery was cycled
from 1.270 to 1.180 through huge resistors three times to soften the
plates. Then, after a good recharging at 600A for 14 hours with a
thermometer in each cell of the gallery, load tested for AH capacity,
further exercising the new plates. Certified cells were then recharged
and gravity-adjusted back to 1.270 before being loaded onto many railroad
cars back to the boats in the drydocks. If you needed hydrogen to fill
your Hindenberg, it was vented out the top of the charging building,
along with GigaBTus of heat by massive fan arrays to prevent explosions.
They still had some impressive "accidents" over the years. An old friend
of mine worked in there for 35 years before retiring from supervision.
He taught me more about batteries than anyone else...lead-acid batteries.

One cool spectacle was that before the old plates could be sent off to
the salvage yard, to prevent salvage yard fires, a huge iron bar was
clamped across the terminals of the cell and left a day. This bar was
about 2" in diameter and glowed BLOOD RED for many, many hours....with
only the electrolyte that hadn't drained out of the separators laying
sideways on a pallet! It eventually stopped and the plates sent off to
salvage...to be recycled by the lead smelters back into battery beasts to
drive the fleet.

Larry
--
I had a Volkswagen Kombi bus camper. Under its back seat was a custom
built deep cycle 8D that filled the compartment, built in that battery
shop by my friend. Sometimes, the charging current from the little
Volkswagen's little, old fashioned, DC generator, dropped almost to 20A!
You could camp all weekend without charging, leaving all the lights on
like a beacon in the night way past midnight, to the amazement of the
tent campers armed with only flashlights....(c; I think I could have
driven the bus home on the starter if the engine failed to start...