Yes, the inverter and alternator put out the correct charge for the Gels.
I also placed a large label on the inverter "Do not equalize!"



"Roger Long" wrote in
:

I'm curious, do you have anything special for a charger or are you
treating them just like regular lead/acid cells?

I went with AGM's because I didn't want to invest in a special voltage
regulator for the gel's. I'm still not sure how necessary that is but
it's what I was being told at the time.

"Roger Long" wrote in news:geKQf.8326$Da7.1067
@twister.nyroc.rr.com:

If a long run under
power with a crude voltage regulator overcharges the wet cells, they
will tolerate it better.

I've never seen a working "crude regulator" overcharge any lead batteries.
The only thing the batteries care about is 14.2V. They'll take care of the
rest (charging current) quite nicely by themselves.

I know what you mean about battery position on Endeavours. The 35' has a
little battery box under the port quarter berth wedged up under the beer
cooler that protrudes into the tiny space under the port cockpit seat. I
used to have to lay on my belly and slide into the berth backwards, after
removing the bedding and pad, then lay there with my face close to the
batteries where I could get blasted in the face if anything happened while
I was looking at the electrolyte level. We moved the house batteries into
the locker under the starboard cockpit seat in a custom box Cap'n Geoffrey
built in his wood shop. At least you didn't have to have your face into
the cell to see it. Of course, you got to unload the locker to get to the
box...(c;

"Larry" wrote

I've never seen a working "crude regulator" overcharge any lead
batteries.
The only thing the batteries care about is 14.2V.

I have. Boiled those suckers half dry. It was the first boat I ever
sailed that even had a battery and I'd borrowed if for a long cruise
with a girl who was just a hell of a lot of fun to be with on a boat
and a great shipmate but turned out to the hound from hell back on
shore. But, I digress. I figured I'd better stop the bubbling and
let things cool down enough that I could touch the battery so I turned
off the battery switch.

Got back, bought my friend a new battery and alternator. A few days
later, I put in a new voltage regulator for him. A couple days later,
another alternator. Then another voltage regulator. The guy in the
marine store said, "Didn't I see you in here the other day? You
should always replace the voltage regulator and the alternator at the
same time. They're eating each other up." Everything was fine after
that but I'd run through about 75% of my net worth at the time. I
used up the rest flying down to Florida to try and convince that girl
to sail with me forever. That was a much bigger mistake than turning
off the battery switch while the engine was running!

--

Roger Long

Hey Wayne,, that is what I was thinking but since I am too dumb to figure
this stuff out; I left it up to you.

Once, long ago, in another time, before ... anyway,, I had a boat with the
switch. The 3 way switch that you could set for battery 1, 2, or both.
Nobody told me and I was young and dumb so I decided to show off for my crew
by switching the knob.

"Look, now I am recharging both and now I am charging one"

Next day,, no alternator.

Live and learn..

JW

--
"Wayne.B" wrote in message
...
On Sat, 11 Mar 2006 13:56:14 GMT, "Roger Long"
wrote:

However, why not disconnect the alternator from the battery circuit
and run it to an inverter large enough to run the dual 10 amp battery
charger?

The alternator needs to always have a load on the output to keep the
voltage from going too high and burning out the diodes (integral to
the alternator). Normally the battery provides this constant load.
The risk is that your inverter might have a mode where it turns off in
some way, leaving the alternator unloaded, and leaving you looking for
a replacement. I'd leave the battery in the circuit, why take a
chance?

On Sun, 12 Mar 2006 12:23:55 GMT, "Thomas Wentworth"
wrote:

Once, long ago, in another time, before ... anyway,, I had a boat with the
switch. The 3 way switch that you could set for battery 1, 2, or both.
Nobody told me and I was young and dumb so I decided to show off for my crew
by switching the knob.

"Look, now I am recharging both and now I am charging one"

Next day,, no alternator.

Live and learn..

Oh yes. I think just about everyone with a boat has had that happen
at one time or another.

It has become my rule that the battery switch is never operated with
the engines running. Period. Doesn't matter if the switch is
"make-before-break", has a field disconnect wire, or there is a
"Zap-stopper" installed. There's always a possibility of failure and
it only takes a few microseconds to zap the diodes and ruin your next
couple of days locating and installing a replacement.

On Sat, 11 Mar 2006 17:20:55 GMT, in message

"Roger Long" wrote:

BTW my AGM's are working great the way I am using them, short motoring
periods and an overnight plug in about once a week to top them up.
With a 20 HP engine and very minimal hotel loads, they don't work hard
anyway. I'm just wondering how they would like being driven by the
low tech Hitachi alternator with its tiny built in regulator if I had
occasion to motor for 12 - 25 hours straight to move the boat
somewhere.

If your concern is over-charging from extended motoring, how about
adding a high current draw accessory that you can turn on whenever you
don't want those amps flowing into your batteries? Just a thought...
I'm sure I can find a way to burn plenty of amps, at least in terms of
the output of a cheap little alternator.

Or read the manufacturer's specs on the AGMs to find out what their
acceptable max continuous charging voltage is and make sure your
regulator doesn't exceed that.

The "Model T" alternator I used to have on my engine (A4) was
regulated to a voltage low enough that it never really fully charged
the batteries, so I could run the engine forever... Sort of the
opposite problem to what you are imagining. I only got full charge
when I got the chance to plug in overnight. You may be in the same
situation.

I would suggest that you partially discharge the batteries, start the
engine, then go for an extended motor cruise. Monitor the voltage
across the batteries and see where it stabilizes. Then make the
assessment about whether or not extended motoring will hurt your
batteries.

Ryk

On Sun, 12 Mar 2006 12:23:55 GMT, in message
vpUQf.183$Vb.56@trndny02
"Thomas Wentworth" wrote:

Hey Wayne,, that is what I was thinking but since I am too dumb to figure
this stuff out; I left it up to you.

Once, long ago, in another time, before ... anyway,, I had a boat with the
switch. The 3 way switch that you could set for battery 1, 2, or both.
Nobody told me and I was young and dumb so I decided to show off for my crew
by switching the knob.

"Look, now I am recharging both and now I am charging one"

Next day,, no alternator.

Perhaps that was before the days of "make before break" battery
switches designed to avoid that problem entirely by always having at
least one battery in circuit at all positions except "off".

Ryk

Ryk,, this was so long ago that Black Beard was in the slip next to me!

===

ps.. Old Black had a nice big cabin cruiser!

====
"Ryk" wrote in message
...
On Sun, 12 Mar 2006 12:23:55 GMT, in message
vpUQf.183$Vb.56@trndny02
"Thomas Wentworth" wrote:

Hey Wayne,, that is what I was thinking but since I am too dumb to figure
this stuff out; I left it up to you.

Once, long ago, in another time, before ... anyway,, I had a boat with the
switch. The 3 way switch that you could set for battery 1, 2, or both.
Nobody told me and I was young and dumb so I decided to show off for my
crew
by switching the knob.

"Look, now I am recharging both and now I am charging one"

Next day,, no alternator.

Perhaps that was before the days of "make before break" battery
switches designed to avoid that problem entirely by always having at
least one battery in circuit at all positions except "off".

Ryk

"Roger Long" wrote in news:d%TQf.8372$Da7.541
@twister.nyroc.rr.com:

I have. Boiled those suckers half dry. It was the first boat I ever
sailed that even had a battery and I'd borrowed if for a long cruise
with a girl who was just a hell of a lot of fun to be with on a boat
and a great shipmate but turned out to the hound from hell back on
shore. But, I digress. I figured I'd better stop the bubbling and
let things cool down enough that I could touch the battery so I turned
off the battery switch.

That was not a WORKING regulator....That was a SHORTED regulator running
the field current at full maximum. The alternator was putting out over
21V open circuit and charging like hell!

Got back, bought my friend a new battery and alternator. A few days
later, I put in a new voltage regulator for him. A couple days later,
another alternator. Then another voltage regulator. The guy in the
marine store said, "Didn't I see you in here the other day? You
should always replace the voltage regulator and the alternator at the
same time. They're eating each other up." Everything was fine after
that but I'd run through about 75% of my net worth at the time. I
used up the rest flying down to Florida to try and convince that girl
to sail with me forever. That was a much bigger mistake than turning
off the battery switch while the engine was running!



The alternators were probably fine. Overcharging doesn't hurt them as
their inherent internal resistance limits their output current to a safe
level unless they are dead shorted, which usually burns the diode
rectifiers.

He was right about replacing the regulator with the alternator. That's
why you should use alternators with BUILT IN regulators....3 connections.
Power on - Ground - Battery. KISS is always the best...(c;

The series pass transistors in the regulator that regulate the field
winding overheat then short emitter to collector, effectively putting the
field winding directly across the battery terminals. This makes the
output voltage of the alternator go to maximum uncontrolled voltage. The
voltage causes heavy charging boiling the batteries (P=IxE - 16V x 80A =
1280 watts!) It melts the cases on some of the plastic batteries. Not
sure how much of this an uncooled AGM or Gelcell could take before it
explodes....They can't boil like a wetcell does, cooling the cell to the
boiling point.

Sorry about the girl....The battery was inconsequential in comparison...
(c;

"Larry" wrote

Sorry about the girl....The battery was inconsequential in
comparison...
(c;

Well, it was a long, long, time ago in a galaxy far, far away.

You brought up a good point though. A similar failure would spray
acid soaked fiberglass mat all over my engine room. Since I don't
have an engineer standing watch to keep an eye on voltages, what would
you suggest for a simple alarm to let me know that things were
starting to go to hell in a handbasket in the voltage department?
Would you try to trip on overvoltage or just measure battery case
temperature directly?

Oh yeah, the other girl I sailed with in that boat:

We went swimming in Edgartown harbor straight out of the bunk if you
know what I mean. I got the sail up on the cat boat and we sailed out
just as we came off the assembly line. It was race week and the fleet
caught up with us and passed us motoring out to the starting line. A
yawl from the Naval Academy passed close along side. Suddenly,
someone barked an order and the entire crew lined the rail, snapped to
attention, and saluted.

There is nothing, absolutely nothing, half so worthwhile as simply
messing around in boats.

--

Roger Long