Here’s one of those wild ideas that will probably get shot down
(probably by Larry) but some of us may learn something from the
patterns the flames make.

I’ve got a nice, temperature compensated, battery charger for running
off the AC at dockside. 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.

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 battery charger then plugs into the AC and one charger
does it all. If I switched off the battery charger, this would also
give me some AC power when the engine was running.

I don’t use AC much and don’t care much for making it by drawing down
my batteries. I wouldn’t mind having the engine idling for the
infrequent times I would like AC away from the dock.

If I could make this work (by switching off battery charging) well
enough to heat up my small hot water heater, which would also be
getting waste exhaust heat (although not much with just 20 HP) , it
would be the nuts.

--

Roger Long

Disregarding the possible merits of the idea, the problem is going to be
matching the alternator output to the inverter. The inverter expects to
see 12 VDC (nominal) but could be designed (could have been designed) to
accept the multi-phase, higher-voltage, frequency-dependent-upon-engine
speed, alternator output.

Your job, should you agree to accept it, is to query the inverter
manufacturers to determine whether their products will accept
unprocessed alternator output. Having established that such units are
commercially available, we can then debate whether the arrangement is a
"good idea".

By way of a preview, depending on an awful lot of awful things, your
Model T-era charging may not be improved much by even the most costly
charger on the market. You might try to establish whether it is the
alternator/regulator combination that is causing your charging
irritation or the unwillingness of your expensive AGM's to accept bulk
charge at the exalted rates of which we dream.

Chuck



Roger Long wrote:
Here’s one of those wild ideas that will probably get shot down
(probably by Larry) but some of us may learn something from the
patterns the flames make.

I’ve got a nice, temperature compensated, battery charger for running
off the AC at dockside. 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.

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 battery charger then plugs into the AC and one charger
does it all. If I switched off the battery charger, this would also
give me some AC power when the engine was running.

I don’t use AC much and don’t care much for making it by drawing down
my batteries. I wouldn’t mind having the engine idling for the
infrequent times I would like AC away from the dock.

If I could make this work (by switching off battery charging) well
enough to heat up my small hot water heater, which would also be
getting waste exhaust heat (although not much with just 20 HP) , it
would be the nuts.

There would probably have to be another voltage regulator in between
the alternator output (from it's standard regulator) and the inverter.

I bought one of those little inverters that go in a cigarette lighter
so I could charge extra cell phone batteries in my car. I have an
unswitched outlet that is on all the time and the charger works great
in that. As soon as I turn the engine on however, the light on the
charger blinks rapidly back and forth from green to red. (charging to
charged). I'm not sure if it's charging but I haven't wanted to risk
the $70 battery and $40 charger to find out.

Sounds like you are pointing me towards similar problems on a much
bigger and more expensive scale.

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.

--

Roger Long

I know this is a serious question and I'm not trying to be a PIA. From
model T's to inverters in one fell swoop. Model T's were hand cranked,
used a spark coil and a magneto (I think).
There was no battery, heater or fuel pump. Basic in black. All in fun
boys

Hey!

Don't you know it is a material violation of usenet rules to post real
facts!

Actually, the T's did have dry cell batteries to aid in generating a
healthy spark while hand-cranking.

But you are dead on in saying that they had no alternators or generators.

Thanks!

Chuck

wrote:
I know this is a serious question and I'm not trying to be a PIA. From
model T's to inverters in one fell swoop. Model T's were hand cranked,
used a spark coil and a magneto (I think).
There was no battery, heater or fuel pump. Basic in black. All in fun
boys

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?

"Wayne.B" wrote

a replacement. I'd leave the battery in the circuit, why take a
chance?


Oh, I have no plans to actually do this. It's just a conceptual idea
I'm throwing out. The whole thing would have to be carefully
designed.

There is a gadget called, I think, a "Zapstopper" to protect the
alternator diodes if your wife's cousin turns the battery switch to
off when you ask him shut off the cabin lights. Something like that
might take care of the concern you raise though.

--

Roger Long

"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;

A little off topic, but..

I'd like to brag about my Gell-cell batteries. The prior owner of the boat
bought them about 14/15 years ago. I tested them again this year, they hold
charge when rested, and supply good power under load, close to new
specifications!

These are 8D Sonnenschein 8D Prevailer Dry-Fit, Gel-Cell.
I'm sure they cost a lot of money 14 years ago, talk about return on
investment!


Larry wrote in
:


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;