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

Another problem would be that the battery peforms as a huge capacitor
for the alternator. The waveforms out of the alternator are pulsing DC,
and the battery will tend to level this out to a straight DC level
which the inverter likes a lot. Without the battery in the circuit, the
alternator may not even start up, as it requires excitation voltage on
the field to start up with. I am not sure about how it will behave with
just pulsing DC for a source either.
Interesting though..anyone want to try it?

Larry DeMers

Wayne.B wrote:

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?

"Roger Long" wrote in news:2GAQf.7687$Zs1.7219
@twister.nyroc.rr.com:

When running for long periods under power
however, my expensive AGM's are being driven by the alternator which
isn't significantly different from the ones on the Model T.
Retrofitting my larger spare with an expensive, 3 stage, temperature
compensated regulator is on my wish list.


Like most boaters who've been sold amazingly overpriced AGM batteries,
you've been duped into thinking they are some amazingly different
technology than the cheap $89 golf cart batteries from Sam's Club.

The AGM battery is not. It's simply a cheaper way of rolling up thin lead
plates with glass mats soaked in the same electrolyte used in all the other
lead-acid batteries. These plates cannot be as thick as the ones in the
golf cart batteries because the big thick plates are very hard to bend.
With so limited an amount of electrolyte, that cannot flow in the gauze and
cool the cell while moving fresh acid in contact with the plates as the
solution of lead sulphate moves away, it matters little how thin the plates
are. To get capacity, the plates rolled up are huge!

BOTH these archaic lead-acid batteries are charged just fine with any
standard alternator with a voltage regulator. They've been working fine
since way before the Model T was produced....(c;

No I wasn't duped. I didn't get the AGM's because I expect any better
electrical performance. Quite the opposite. I know that standard wet
cells carefully tended by a knowledgeable person equipped with
hydrometers, thermometers, bottles of distilled water, flashlight,
face shield, and internet connection will give better performance and
cost less than anything out there.

I just don't want to muck around with all that stuff (if you could see
where my batteries are, you would know why. I also don't want free
liquid acid and batteries with a space that gas can mix with oxygen
above the acid in my boat. I know that I'm paying a price in both
money (lots) and performance (slight) for the convenience and safety.

One of the compromises, as you have pointed out, is that the wet cells
are much better at cooling themselves because the liquid electrolyte
can convect around and carry heat to the surface. If a long run under
power with a crude voltage regulator overcharges the wet cells, they
will tolerate it better. If they do boil off some electrolyte, I
would discover it and correct it the next time I wanted to get warm
and fuzzy with my batteries. With AGM's, I'll just be moving the next
expensive replacement a bit closer. Thus, I want to be sure that I am
charging them very carefully.

--

Roger Long



"Larry" wrote in message
...
"Roger Long" wrote in news:2GAQf.7687$Zs1.7219
@twister.nyroc.rr.com:

When running for long periods under power
however, my expensive AGM's are being driven by the alternator
which
isn't significantly different from the ones on the Model T.
Retrofitting my larger spare with an expensive, 3 stage,
temperature
compensated regulator is on my wish list.


Like most boaters who've been sold amazingly overpriced AGM
batteries,
you've been duped into thinking they are some amazingly different
technology than the cheap $89 golf cart batteries from Sam's Club.

The AGM battery is not. It's simply a cheaper way of rolling up
thin lead
plates with glass mats soaked in the same electrolyte used in all
the other
lead-acid batteries. These plates cannot be as thick as the ones in
the
golf cart batteries because the big thick plates are very hard to
bend.
With so limited an amount of electrolyte, that cannot flow in the
gauze and
cool the cell while moving fresh acid in contact with the plates as
the
solution of lead sulphate moves away, it matters little how thin the
plates
are. To get capacity, the plates rolled up are huge!

BOTH these archaic lead-acid batteries are charged just fine with
any
standard alternator with a voltage regulator. They've been working
fine
since way before the Model T was produced....(c;

"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

"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,

I ruined four golf cart T105's last summer by overcharging them. I
have a Balmar alternator and MH612 regulator. This regulator has a
separate wire that goes to the common positive input to my batery
combiner, and is the 12vdc reference voltage for the regulator. The
lead has an in-line fuse which corroded at one contact, interrupting the
12vdc reference signal to the regulator, and it then went open field to
17v!! We eventually smelled the hydrogen being produced..and awful tangy
smell that is unmistakeable. The plates of the battry actually warped
accordian fashion, and my capacity went from around 100aH (to 12.0v)
down to 35 aH before 12.0v. So replaced them, and the reference leads
fuse assembly. Balmar provided a replacement holder that is much
better, and sealed too.

But they did overcharge a couple times (the symptom came and went due
to vibration giving a good connection sometimes, and a bad one
occasionally. I found it only by chance) causing their being ruined.

Larry DeMers
s/v DeLaMer
Lake Superior

Larry wrote:

"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;

In article ,
Larry DeMers wrote:

We eventually smelled the hydrogen being produced.

Yea, right, would you like to try again for what is behind
Door No. 3.....

What you smelled was the Sulfur Dioxode boiling off.....