On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

Having a boat is about making your own choices.
But you might be better off to listen to the people who say
that gas is the way to go with cooking and water heating.

Some folks would hold out for a gas fridge too, I expect.
Using electricity is OK for heating if somebody else has
the chore of generating the juice.
You don't have that luxury.

Brian W

On Sat, 10 Jan 2004 22:20:53 GMT, misia
wrote:

On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

You are going to find out that heating things with electricity takes a lot
of it. That is why gas is used on boats, mobile homes, etc for things that
heat. And why most people run their gensets when using appliances. AC's
use a lot of power too but you might get away with it. Consider this, a
1200 watt electric heater is drawing 10 amps at 120 volts. Drop the voltage
down to 24 volts and now you need 50 amps. I will not tell you it is
impossible but you will need a lot of batteries.

"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

HI Mi,
You have run hard aground on the 24 volt appliances. The selection is
slim. Your best bet is an inverter, 12 volt charger and 12 volt house
battery, Then utilize 110/12 volt appliances. Don't forget use 12v
breaker(s). It would cost you less in the long run. Also, having a
decent inverter (5000 watts or so will allow you to run your air
conditioner, hot water heater or stove as necessary.

Have a look at the link below.

http://www.cetsolar.com/dcappliances.htm

Good Luck,

Capt. Frank
la Dolce Vita

http://www.home.earthlink.net/~aartworks



misia wrote:
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

Wouldn't actually make much of a difference. If the 2KW water heater
were running on 12V, it would draw 167A. On 24V it would still draw
83.3A, draining the batteries in a matter of minutes, not hours......

Then, comes the problem of battery real estate. in the same space it
takes to put 500 amp-hours of 12V batteries, you get 250 amp-hours of
24V batteries.....the same exact kilowatt-hour rating. If you
parallel two 130AH 12V deep cycles, you get 260AH at 12V. If you
series them, you get 130AH at 24V......the same exact power output in
KwH. You can use smaller wire, though....(c;

Running large electrical loads of batteries is a pipe dream on these
boats at any voltage. There just isn't room for a proper battery
bank, like you'd need. A 350AH large golf cart battery, which is only
6 volts, is only 2.1Kwh but at a very low rate like 20A, not 200A. We
run 4 of these monsters in 2 banks in series-parallel to get 12V at
700AH in Lionheart's engine room. You can't use all 700AH because
that would really shorten their life, so you only discharge them about
400-500AH before charging, and that's stretching it. Then, it's so
hard to get that last 15% to full charge, there's no point running the
charging engine for hours more so you lose 15% more capacity charging
them only up to 85% of full specific gravity. This battery bank of 4
is about 4' x 20" x 24" tall and 400 pounds of ballast. In
comparison, each CELL of 126 cells in a WW2 submarine is about 7' high
by 4' by 3' and puts out 2V at 6,250AH to drive the sub 48 hours at
only 2 knots on TWO 126 cell banks...one forward, one aft. WW2 subs
carried nearly 1000 TONS of batteries to accomplish this level of
power. No wonder they sank a perfectly good boat!

With an 80A alternator running flat out, you can recharge Lionhearts
400AH "standard discharge" in about 5.5 hours. Charging too fast, and
this is almost too fast, makes charging more dangerous (heat) and
boils off the electrolyte (hydrogen). With a tapering charge, it
takes longer...6-7 hours. At 80A, the fanbelt better be TIGHT!
Charging monster battery banks is another problem altogether.....

Nothing is funnier than a boater with a new 4KW inverter carrying his
electric heater down the dock with a big smile on his face.......

The real answer is a super quiet insulated diesel genset with a small
starting battery and a hundred gallons of #2 fuel oil.....an immense
pool of liquid power...(c; The Navy prefers nuclear power but the
refueling is messy.



On Sat, 10 Jan 2004 22:20:53 GMT, misia
wrote:

On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

When we got Lionheart, it came from San Francisco. It had a
rotted-out diesel heater to keep it warm. Sitting right next to this
waste of good diesel fuel, was a Perkins 4-108 diesel heater POURING
heat into its exhaust system so much they had to pour seawater into
the exhaust to cool it.

I've never figured out why boats in cold climates waste all this
energy going out the exhaust. It's SO easy to make a cast iron heat
exchanger in a dry stack, right next to...or even right IN the exhaust
manifold that will just roast your ears with free heat.

We retrieve some of it with the hot water heater hooked to the water
jacket. Too bad so much heat is simply wasted.

I have an electronics shop built into a surplus Air Force stepvan. My
shop heater in winter is a 1KW Honda EU1000i power plant. I welded a
pipe nipple on the little exhaust port with an elbow on the end. This
connects to a copper tubing draining the exhaust gases out the deck
under the truck. Keeps the shop toasty warm while providing me up to
1KW of 120VAC to run my equipment.....I figure I recover 85-90% of the
heat produced by the engine. Its quiet enclosure makes an acceptable
sound level to work in hidden away behind the cabinets.



On Sun, 11 Jan 2004 01:16:43 GMT, "Lawrence James"
wrote:

You are going to find out that heating things with electricity takes a lot
of it. That is why gas is used on boats, mobile homes, etc for things that
heat. And why most people run their gensets when using appliances. AC's
use a lot of power too but you might get away with it. Consider this, a
1200 watt electric heater is drawing 10 amps at 120 volts. Drop the voltage
down to 24 volts and now you need 50 amps. I will not tell you it is
impossible but you will need a lot of batteries.

"misia" wrote in message
mail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

Mi,
I completely agree with you. Electric is the way to go for both safety and
convenience. I would not have gas unless CNG was available everywhere and
there is the rub. It isn't. The gas of popular choice is LPG and that is
heavier than air. CNG is not. So for me, the best of the rest was electric.
The other responders mentioned the impractcality of using 24V for heating
and cooking. They are correct. In order to be all electric, you must use
240V. Even 120V is impractical because of the wire size required. You need a
large generator, in fact you probably need 2. That means a big boat. The
other problem is the noise from a running generator. I have overcome this
problem with a shaft driven 6KW generator that is silent and a 35KW diesel
generator, but then I have the space. Please be careful of capturing heat
from your engine exhaust. Yes, it is possible, but if you take to much heat
out, you will create acidic deposits that will destroy 316. If you use a
fresh water exchanger and your hot water tank is up to temp and you continue
to run the engine, the exchanger overheats. So you need auxillary cooling,
when your heat demand is low. I guess there is no free lunch.
Steve
"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I wantMi,
to go totally electric (no gas)

Regards Mi

Steve Lusardi wrote:

If you use a
fresh water exchanger and your hot water tank is up to temp and you continue
to run the engine, the exchanger overheats. So you need auxillary cooling,
when your heat demand is low. I guess there is no free lunch.

??? Are you suggesting there are systems out there that use
the domestic hot water system as a heat sink for the engine
cooling requirements? Or that someone would install a heat
exchanger that is rated at a lower temperature than the
operating temperature of the engine cooling circuit?

Something is missing here.

Rick

That means a big boat.

Thanks to all posters for feedback.
I have the luxury of a big cat and big battery bank.

I'm not worried about the fridge , it's maybe 300W/24 hrs average in tropics
and half of this in the north.

As for the cooker- two hot plates at 1KW each seems a lot but given you use it
for 1 hour/day it translates to something like 2kW/24 = 83 Watts average @ 24
hrs and I think it's well worth it given the safety,cost, convenience and
simplicity advantages.

Same goes for coffee maker etc.

I did do my math before posting here and I understand how amps/watts etc add up.
I agree higher voltage would be nice but we are stack with 24V and don't expect
to be running generator at all times. Also we have luxury of designing
everything from scratch as the boat is being built and can acommodate locations.
In other words instead of long thick wires we can make them short for equipment
which consumes a lot of ampers. I'm trying to be smart but not always
conventional with this.

I agree electric heater might be the most energy hungry element, especially if
the water has to be retained and temperature maintained in the tank for 10
people onboard.

This is something that I'm considering to built around hybrid solution.

I came accross this Webasto heater:

http://www.navstore.com/pdf/webasto/Webasto%20TSL17.pdf

What do you think?

Another thing is - I'm wondering if we need a water tank at all? It takes lost
of gallons to shower 10 people- it cost money and space. I remember seeing in
some country (not US) showers with built in electric heater element which will
simply just warm up water passing through a piece of the size of grapefruit.

Regards M

Steve Lusardi wrote:

Mi,
I completely agree with you. Electric is the way to go for both safety and
convenience. I would not have gas unless CNG was available everywhere and
there is the rub. It isn't. The gas of popular choice is LPG and that is
heavier than air. CNG is not. So for me, the best of the rest was electric.
The other responders mentioned the impractcality of using 24V for heating
and cooking. They are correct. In order to be all electric, you must use
240V. Even 120V is impractical because of the wire size required. You need a
large generator, in fact you probably need 2. That means a big boat. The
other problem is the noise from a running generator. I have overcome this
problem with a shaft driven 6KW generator that is silent and a 35KW diesel
generator, but then I have the space. Please be careful of capturing heat
from your engine exhaust. Yes, it is possible, but if you take to much heat
out, you will create acidic deposits that will destroy 316. If you use a
fresh water exchanger and your hot water tank is up to temp and you continue
to run the engine, the exchanger overheats. So you need auxillary cooling,
when your heat demand is low. I guess there is no free lunch.
Steve
"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I wantMi,
to go totally electric (no gas)

Regards Mi


CNG is not heavier than air???


--

A friend is someone who knows you, understands the essential conflicts in your
thinking, in your morals, and in your philosophy, and like you anyway.