Don W wrote in news:bjfmg.153139$F_
:

Hmm... 3 ton submarine cells. Too bad we couldn't
talk the manufacturers into making my 8500 lb keel
into one big lead acid battery ;-)



Call Electric Boat!

Electric Boat Corp
75 Eastern Point Rd
Groton, CT zip code
Phone: (860) 433-3000

They've got lots of experience with submarine battery banks....(c;

"Can we build one for you?"

On Thu, 22 Jun 2006 09:45:43 -0400, Larry wrote:

Call Electric Boat!

Electric Boat Corp
75 Eastern Point Rd
Groton, CT zip code
Phone: (860) 433-3000

===================

Better yet:

http://www.duffyelectricboats.com/

Wayne.B wrote in
:

http://www.duffyelectricboats.com/


Wow...Rolls Batteries (Would you use anything else in a Duffy?!) lists 8D
batteries between $433 and $907 each on:
http://www.staabbattery.com/rolls_de...atteries.shtml
We'll need the biggest capacity superbattery as only the best will do.

$907 each times 16 batteries equals $14,512 if you replaced them TODAY.
With a 7 year warranty that's conspicuously missing from the warranty
explanation webpage I'm not sure how long the REPLACEMENT warranty actually
is, but from the look of the other batteries, a 72 month battery only
replaces for 18 months. Beyond that it is pro rated down to nothing at 72
months. Anyone had an old Rolls deep cycle like the 8D replaced by them?

If they last 3 years before the capacity starts limiting cruising range
uncomfortably, at today's awful inflation rate over the next 3 years of,
say, 15%, replacement's gonna cost you around $16,000 to 17,000 PLUS
INFLATION EVERY 3 years....or so...

Sure makes what the boatyard told you it was gonna cost to overhaul the old
3 cyl Yanmar look real cheap after 7000 hours, doesn't it?

And, curiously, the Yanmar doesn't eat itself just sitting at the dock like
lead-acid batteries do.

OUCH!

On Thu, 22 Jun 2006 23:39:47 -0400, Larry wrote:

If they last 3 years before the capacity starts limiting cruising range
uncomfortably, at today's awful inflation rate over the next 3 years of,
say, 15%, replacement's gonna cost you around $16,000 to 17,000 PLUS
INFLATION EVERY 3 years....or so...

Rolls batteries typically last 7 to 10 years if well cared for. We
are *not* talking Walmart quality here. Most of the folks who buy
those beautiful little Duffy boats are old enough that 7 to 10 years
is as good as a lifetime warranty.

Roger Long wrote:
Larry,
snip RV heat pump advice for sailors
I put this post quite well up on my mental list of the ten best posts
ever to the forum.

I would also add KUDOS to common sense, a commodity often absent from
gold plated boaters with unqualified aspirations to snobbery. Hint:
real snobs don't need bling.

As an unconcerned snob, far too snobbish to usually involve one's self
with stupid people, I have however been unavoidably forced to
contemplate some issues of stupidity WRT heating and cooling and
energy.

The question in this vein begs expression: why do not all air
conditioners include the obviously useful option of being reversible?
Why do people not insist on this option?

To use an air conditioner as a heating appliance seems to me to be so
basic an idea thet there must be a conspiracy of stupid marketing
people to not advertise this as an option to save energy for heating,
and of course, money.

If every a/c could be switched to a heat pump function the energy saved
in winter, spring and fall heating applications would surely be
significant on a national scale, even if all we did was to reverse the
mounting in our window units and control the heating function by
unplugging it. Pumping heat is cheaper than creating it.

Why does not every a/c unit include provision to use it as a heater?

It's a national scandal of stupidity, especially given the efficiency
placards we see on refrigerators, stoves, etc. It's a scandal because
the efficiency would figure so obviously in an energy short world, or
just in dollars spent for heat.

Possibly a reversible control panel would be cheaper than reversible
valving solenoids or manual valves, even if, as some will say, it won't
work in a cold winter because of the freon, etc, etc, it would be worth
it if you do the math, even if the freon used were a little more
expensive.

Sometimes and once again, CHEAP is BETTER. It is only stupidity that we
do not, did not start on this 50 years ago.

Terry K

I do realize how many amps, but I have a DC generator and don't want to
run the thing on an inverter.

Mike

Do you realize how many amps a 6000 btu air conditioner would require at
12 volts? Hey Larry, they don't just take heaters to the boat.
krj

Wayne.B wrote in
:

Rolls batteries typically last 7 to 10 years if well cared for. We
are *not* talking Walmart quality here. Most of the folks who buy
those beautiful little Duffy boats are old enough that 7 to 10 years
is as good as a lifetime warranty.



Running sailboat lighting, the stereo and some electronics with the
intermittent load of the bilge pump and inverter is a far cry from
running a 20 horsepower DC propulsion motor pulling a large boat at 8
knots, discharging the hell out of the Sooperbatteries in the process.

Guessing, using the standard 846 watts/hp, 20hp = 16,920 watts divided by
the 96 volts all the series batteries produce = 176 (and change) AMPS if
you're running it at 8 knots, wide open. Wanna bet they get HOT?!

Pouring out 180 amps from a plastic cased lead-acid battery, subject to
physics and chemistry no amount of advertising hype can contradict, I
submit there's no way a Rolls sooper-dooper battery will survive 7 years
of this abuse, which amounts to connecting your Rolls house batteries to
the starter motor and driving home without diesel fuel every time you run
the boat.

I'd love to test this theory if Rolls is willing to fund the Duffy and
$14,000 worth of Rolls batteries for an honest test, however. LET THE
DEEP CYCLING BEGIN!

I see the accessories all run off yet another $900 house battery. I
didn't add that figure in because every boat has those.

The damned battery supplies from anywhere seem to go flat when someone
shows up with the simplest calculator and ohms law asking embarrassing
questions why the 4KW inverter can't run 2 ton of air conditioning off
$15,000 in batteries....(c;

On Fri, 23 Jun 2006 15:12:59 -0400, Larry wrote:

Running sailboat lighting, the stereo and some electronics with the
intermittent load of the bilge pump and inverter is a far cry from
running a 20 horsepower DC propulsion motor pulling a large boat at 8
knots, discharging the hell out of the Sooperbatteries in the process.

Guessing, using the standard 846 watts/hp, 20hp = 16,920 watts divided by
the 96 volts all the series batteries produce = 176 (and change) AMPS if
you're running it at 8 knots, wide open. Wanna bet they get HOT?!

Your numbers are off a bit. Around here these things get driven by
little old men and ladys around the canals for a few hours on Sunday
afternoon when the grand children are visiting. Average speed is
probably about 5 kts which requires no more than 3 or 4 hp with an
easily driven hull.

Figure 4,000 watts give or take, around 40 amps, no heat generated, no
animals killed, injured or abused. After 3 hours the batteries are
still at greater than 50%. These things do not get taken off shore.

:-)

"Terry K" wrote in news:1151068708.100276.227550
@m73g2000cwd.googlegroups.com:

Why does not every a/c unit include provision to use it as a heater?



Most have strip heaters in them, or have it an available option.....

A heat pump needs, well, heat to function well. Here in the South we
heat our homes with heat pumps. But, alas, they only work good down to
about 40F outside air temperature, then the evaporator (the outside unit
of the reversed cycle) starts to freeze up requiring us to temporarily
reverse it again to boil off the ice that forms on the outside coils.
They call it "Defrost Cycle". I've always called it "Freeze Your Ass
Cycle" as really COLD air comes out of my vents when it's going on.

Boats with heat pumps work great in Charleston because the water from the
Atlantic is always WARM, even in January. The water never gets below
about 50F for long, so the warm water pumping through the water-cooled
heat pump keeps it from freezing up. If a water-pumped heat pump ever
DOES freeze up, say from the creepy crawlers plugging up the seawater
strainer, for instance, or the seawater pump failing, an amazingly fast
block of ICE forms INSIDE the seawater heat exchanger, which is just
tubing, after all. This ice, of course, does what ice likes to do,
expand and rip open any "pipe" it freezes in, including the amazingly
expensive seawater heat exchanger.

Another reason I don't like it is the damned maintenance, especially
going to the boat in winter to clean the creepy crawlers out of the
strainer so often. Even in winter they colonize a strainer here as they
get sucked in. One good reason for that is the ones trapped in the
strainer are warmer than the ones outside the boat, I suspect. They seem
to relish in the warmth of the strainer.

Electric heat, heat strips, suffers from none of these problems. When's
the last time you took your electric heater apart to clean it out?
Mostly never?

Now, economics. Noone gives a rat! They're paying for dock space with
50A of 120VAC for a god-awful amount each month. If the electric bill on
the boat is $200/month or $20, who cares? Boaters with electric meters,
excepted, running strip heat in the boat simply drops marina profits.
It's cheap heat when someone else is paying for the power to run
it...especially if you factor in the boater's expense of heat pumps,
maintenance, the damned seawater pump that has a MTBF of 150 hours,
cleaning out strainers on a freezing, deserted dock on Feb 2nd in the
gale.

It's not an issue "Up Nawth", anyway. With a seawater temperature of
33F, the heat pump is nearly useless as its seawater heat exchanger
freezes below the water freezing point and it either has to do frequent
reverses of the cycle to deice it or just freeze it solid.....

On Fri, 23 Jun 2006 15:12:59 -0400, Larry wrote:

///
Guessing, using the standard 846 watts/hp, 20hp = 16,920 watts divided by
the 96 volts all the series batteries produce = 176 (and change) AMPS if
you're running it at 8 knots, wide open. Wanna bet they get HOT?!
//

Make that 746 watts per horse

Brian Whatcott Altus OK