" wrote in news:7f8aa6de-0499-4d2c-
:

Well, I've got two 110 amp alternators on a 510 AH bank and I think
that's about right. My experience is that I can bulk my batteries
quickly with my 110's. Sometimes I top them off with solar and
sometimes I work them in the 80%-50% range. Every week or so they get
a full charge and that does take a long time, but still less time than
it would with a 60 amp unit. YMMV.

-- Tom.



Tom, how are you measuring these percentages? Are you using a hydrometer?

On Jul 18, 9:28 pm, Larry wrote:
" wrote in news:7f8aa6de-0499-4d2c-
....
Tom, how are you measuring these percentages? Are you using a hydrometer?

Zen. Well, I have an Ample Power computer but it only gives a general
feel. I've got AGM's so a hydrometer is out. Anyway, I didn't mean
for the percentages to be taken very exactly. When the batteries are
low I can throw a couple hundred amps at them for 15 minutes or so and
the absorption drops off pretty slowly. I figure until the rate is
down to 60 or so I'm saving charge time over what I'd be doing with a
normal alternator. One of the joys few joys of lead acid is that you
don't need to top them off each time you charge them. Every week or
so is fine. My feeling is it takes much less time to get charge the
bank to a 15 amp acceptance with the 110's over what it would with a
sixty...

-- Tom.

" wrote in news:1bbb3540-d522-4939-
:

When the batteries are
low I can throw a couple hundred amps at them for 15 minutes or so and
the absorption drops off pretty slowly.

200A x 12V = 2,400 watts.

No danger of overheating and warping AGM plates with only 2.4 kilowatts
forced into them at all. You should crank up the charging even further.

SARCASM OFF

If you ever get a chance to look around inside a sailboat where the battery
has exploded, don't miss this lesson in humility.

It's amazing how the middle spoons in a neat stack of "stainless" spoons is
pitted and eaten just like the ones on the ends, in a closed drawer,
outside the battery box, on the other side of the boat from the exploding
battery. Even the bellcrank on the rudder post had acid damage on it.

You gotta see it to become a believer.....

......and stop cooking lead acid batteries for life!

On Jul 19, 2:32*pm, Larry wrote:
...
200A x 12V = 2,400 watts.

No danger of overheating and warping AGM plates with only 2.4 kilowatts
forced into them at all. *You should crank up the charging even further..
...

Just for the record, my electrical system was designed and installed
by Gary Pacey of Outback Marine. He's an EE specializing in marine
power systems. He's installed virtually the same system on lots of
boats. In the small world category, the boat three down the dock from
us was built in the same year in the same part of Oz and with the same
power system as my boat. I know Gary did a lot of in house testing and
had good relationships with the suppliers of the batteries and
controllers. In short, this isn't something that I just threw
together out of catalogs.

Also, I don't follow you point. Are you saying 2.4Kw is too much
power for any battery bank or were you making a specific point?

-- Tom.

On Sat, 19 Jul 2008 16:02:44 -0700 (PDT), "
wrote:

On Jul 19, 2:32*pm, Larry wrote:
...
200A x 12V = 2,400 watts.

No danger of overheating and warping AGM plates with only 2.4 kilowatts
forced into them at all. *You should crank up the charging even further.
...

Just for the record, my electrical system was designed and installed
by Gary Pacey of Outback Marine. He's an EE specializing in marine
power systems. He's installed virtually the same system on lots of
boats. In the small world category, the boat three down the dock from
us was built in the same year in the same part of Oz and with the same
power system as my boat. I know Gary did a lot of in house testing and
had good relationships with the suppliers of the batteries and
controllers. In short, this isn't something that I just threw
together out of catalogs.

Also, I don't follow you point. Are you saying 2.4Kw is too much
power for any battery bank or were you making a specific point?

-- Tom.


Not to disparage anyone but have a look at the battery manufacturer's
specs and see whether they recommend that high a charging rate. I
suspect you'll see something like 10 - 15% of rated capacity.


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

On Jul 19, 5:04*pm, Bruce in Bangkok
wrote:
...
Not to disparage anyone but have a look at the battery manufacturer's
specs and see whether they recommend that high a charging rate. I
suspect you'll see something like 10 - 15% of rated capacity.
...

Nope. My battery manufactuer recommends charging with a voltage
regulated charger at 14.2-14.4 volts.* That's what I do. And as I
say, many other boats are doing this, too. It has worked well for me
for years and AFIK it works well for other folks also.

Not to disparage anyone, but where are you getting your information?
You sound very sure of yourself. However, what you are saying doesn't
fit with my experience or with the advice I have taken from a pro. Do
you have any sources or experience you can point to?

-- Tom.

*http://www.lifelinebatteries.com/mch...procedures.php

On Sat, 19 Jul 2008 18:52:14 -0700 (PDT), "
wrote:

On Jul 19, 5:04*pm, Bruce in Bangkok
wrote:
...
Not to disparage anyone but have a look at the battery manufacturer's
specs and see whether they recommend that high a charging rate. I
suspect you'll see something like 10 - 15% of rated capacity.
...

Nope. My battery manufactuer recommends charging with a voltage
regulated charger at 14.2-14.4 volts.* That's what I do. And as I
say, many other boats are doing this, too. It has worked well for me
for years and AFIK it works well for other folks also.

My battery manufacturer recommends charging to 14.8 and then dropping
back to 13.2, see:

http://www.trojan-battery.com/Batter.../Charging.aspx

If you stop when the batteries first reach 14.8 you never fully charge
your batteries.


Not to disparage anyone, but where are you getting your information?
You sound very sure of yourself. However, what you are saying doesn't
fit with my experience or with the advice I have taken from a pro. Do
you have any sources or experience you can point to?

Try
http://www.trojan-battery.com/Batter...Selection.aspx

Note that my figures were too low for some batteries. Trojan
recommends 20% but other recommendations are in the 10 - 15% range
see: http://www.solarnavigator.net/battery_charging.htm


-- Tom.

*http://www.lifelinebatteries.com/mch...procedures.php

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Bruce in Bangkok wrote:

Not to disparage anyone but have a look at the battery manufacturer's
specs and see whether they recommend that high a charging rate. I
suspect you'll see something like 10 - 15% of rated capacity.


That's what Trojan says for their wet cells, though I've done a lot of
charging at more like 18-20% will no ill affects. My first set did die
after 7 years (they might have gone another year or so if I had tended
to them better over a harsh winter), but frankly, they are the cheapest
part of the system.

For their gel and AGM batteries, they say 20%.

On Sat, 19 Jul 2008 22:33:47 -0400, jeff wrote:

Bruce in Bangkok wrote:

Not to disparage anyone but have a look at the battery manufacturer's
specs and see whether they recommend that high a charging rate. I
suspect you'll see something like 10 - 15% of rated capacity.


That's what Trojan says for their wet cells, though I've done a lot of
charging at more like 18-20% will no ill affects. My first set did die
after 7 years (they might have gone another year or so if I had tended
to them better over a harsh winter), but frankly, they are the cheapest
part of the system.

For their gel and AGM batteries, they say 20%

From all I can read the rate of charge is determined more by what it
is doing to the electrolyte then anything else. If you read up on car
alternators you will read many references to "without excess water
loss". So, probably if your batteries aren't getting hot and aren't
gassing excessively the current is not excessive. I think I read
somewhere 120 degrees F was the hottest allowable.

But the point Larry keeps making, and every competent description I
have ever read about lead acid batteries emphasizes is that because
the process is a chemical process it takes some time to accomplish. No
matter how many amps of current you blast in there it still takes time
to convert the plate material back to it's original state.

Try .http://www.batteryfaq.org/ for more information then you ever
wanted to know about batteries.

The writer sells various battery meters, combiners, regulators, etc.,
but his writing is impartial and very informative.


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

On Sat, 19 Jul 2008 16:02:44 -0700 (PDT), "
wrote:

On Jul 19, 2:32*pm, Larry wrote:
...
200A x 12V = 2,400 watts.

No danger of overheating and warping AGM plates with only 2.4 kilowatts
forced into them at all. *You should crank up the charging even further.
...

Just for the record, my electrical system was designed and installed
by Gary Pacey of Outback Marine. He's an EE specializing in marine
power systems. He's installed virtually the same system on lots of
boats. In the small world category, the boat three down the dock from
us was built in the same year in the same part of Oz and with the same
power system as my boat. I know Gary did a lot of in house testing and
had good relationships with the suppliers of the batteries and
controllers. In short, this isn't something that I just threw
together out of catalogs.

Also, I don't follow you point. Are you saying 2.4Kw is too much
power for any battery bank or were you making a specific point?

-- Tom.

Larry is possibly supposing that the 50 ampere hours you are charging
with will show up as 2.4 kW of heat - but he will remember that most
of that energy goes to electrochemical storage.
Still, give a person credit for gun-shyness from a battery fast-charge
accident!

Brian W