* Larry wrote, On 8/10/2007 5:36 PM:

This telling little paragraph is why we still have an electrical problem
on the Pig. As soon as we start the engine, we crank it all up BEFORE
the heavy battery charge current and 13V turns into light charge current
and the alternator's voltage regulator starts throttling back rotor
current to limit the voltage to 14.2V.....

Is it any wonder that you're eating V-belts keeping the poor alternator
at its limit BEFORE the battery charging is complete?!

I love you two to death, but we have GOT to stop using our recharging
current to run all that crap! NO UNNECESSARY LOADS UNTIL THE BATTERY
VOLTAGE RISES TO REGULATOR VOLTAGE! RECHARGE THE BATTERIES FIRST!!

I believe this is total nonsense. I have one major load, a
fridge/freezer that draws about 30 Amps and runs about an hour to
three hours a day (depending on air and water temps, etc.). I make a
point of running the engine or generator at the same time as the
fridge, thus saving about 15 to 20% of the power - the efficiency loss
of running the juice through the batteries. In addition to the simple
Charge Efficiency Factor, there is also the issue of running the
fridge at 13+ Volts, as opposed to 12 (or even less) Volts. There is
no indication that the alternator runs harder doing this, in fact its
running about 20% less.

Oddly, you're always claiming that charging a 450 Ah bank at 80 or 90
Amps is doing great damage. What I'm doing is reduces that to 50 Amps
charging, with 30 Amps to the fridge. Are you claiming that the
fridge, radar, and autopilot must be turned off if the engine is
running and the batteries are not fully charged?

"Jeff" wrote in message
...
* Larry wrote, On 8/10/2007 5:36 PM:

This telling little paragraph is why we still have an electrical
problem on the Pig. As soon as we start the engine, we crank it all
up BEFORE the heavy battery charge current and 13V turns into light
charge current and the alternator's voltage regulator starts
throttling back rotor current to limit the voltage to 14.2V.....

Is it any wonder that you're eating V-belts keeping the poor
alternator at its limit BEFORE the battery charging is complete?!

I love you two to death, but we have GOT to stop using our recharging
current to run all that crap! NO UNNECESSARY LOADS UNTIL THE BATTERY
VOLTAGE RISES TO REGULATOR VOLTAGE! RECHARGE THE BATTERIES FIRST!!

I believe this is total nonsense. I have one major load, a
fridge/freezer that draws about 30 Amps and runs about an hour to
three hours a day (depending on air and water temps, etc.). I make a
point of running the engine or generator at the same time as the
fridge, thus saving about 15 to 20% of the power - the efficiency loss
of running the juice through the batteries. In addition to the simple
Charge Efficiency Factor, there is also the issue of running the
fridge at 13+ Volts, as opposed to 12 (or even less) Volts. There is
no indication that the alternator runs harder doing this, in fact its
running about 20% less.

Oddly, you're always claiming that charging a 450 Ah bank at 80 or 90
Amps is doing great damage. What I'm doing is reduces that to 50 Amps
charging, with 30 Amps to the fridge. Are you claiming that the
fridge, radar, and autopilot must be turned off if the engine is
running and the batteries are not fully charged?


I must inform you if your fridge draws 30 amps at 13VDC then there's
something seriously wrong with it. Mine only draws 5 amps. Hell, you
could run an air conditioner on 30 amps.

Wilbur Hubbard

* Wilbur Hubbard wrote, On 8/10/2007 6:46 PM:
....

I must inform you if your fridge draws 30 amps at 13VDC then there's
something seriously wrong with it. Mine only draws 5 amps. Hell, you
could run an air conditioner on 30 amps.

It would seem that we can add yet another topic to the long list of
nautical issues where you seem completely ignorant.

First of all, 30 Amps DC won't get you a lot of A/C, though I must
admit I haven't looked into to smaller units. (The smallest one West
has would be about 50 Amps DC for 5000 BTU.)

However, a 30 Amp draw is quite common for my type of fridge. Its a
1/2 HP motor driving a compressor that feeds several holding plates in
a 9 cu ft fridge and 5 cu ft deep freeze. The actual load varies from
20 to 35 Amps. Here in Maine I've been monitoring it carefully, and
it has taken about 40 Amp-hours per day for the last two weeks. The
fridge stays at 42-46 degrees, the freezer at 15-20, both measured at
the top shelf.

Your system probably has a Danfoss hermetic system and runs about half
of the time, depending on the load, so you actually use about 60
Amp-hours a day. And your fridge/freezer is probably half the size
of mine, and not as cold.

Frankly, I've been thinking that is I did my system today I might use
two modern Danfoss systems, so I could shut down the freezer when not
needed. However, the last time I charged it up I seem to have got it
right and the efficiency is quite high. I curious to see how it works
when we get back into warmer waters in a week.

"Jeff" wrote in message
...
* Wilbur Hubbard wrote, On 8/10/2007 6:46 PM:
...

I must inform you if your fridge draws 30 amps at 13VDC then there's
something seriously wrong with it. Mine only draws 5 amps. Hell, you
could run an air conditioner on 30 amps.

It would seem that we can add yet another topic to the long list of
nautical issues where you seem completely ignorant.

And it would seem you're drawing conclusions based on scanty information
yet again.


First of all, 30 Amps DC won't get you a lot of A/C, though I must
admit I haven't looked into to smaller units. (The smallest one West
has would be about 50 Amps DC for 5000 BTU.)

However, a 30 Amp draw is quite common for my type of fridge. Its a
1/2 HP motor driving a compressor that feeds several holding plates in
a 9 cu ft fridge and 5 cu ft deep freeze. The actual load varies from
20 to 35 Amps. Here in Maine I've been monitoring it carefully, and
it has taken about 40 Amp-hours per day for the last two weeks. The
fridge stays at 42-46 degrees, the freezer at 15-20, both measured at
the top shelf.

What you're doing is pretty wasteful. Sounds like you have a separate
freezer and refigerator. That's dumb. All you need is a freezer that
connects to your fridge box with a well-insulated duct. Keep your
freezer full of meats and other dense stuff and run it all the time.
Allow some of the excess cold air to migrate into your fridge box by
controlling the size of the duct. The duct should run from the top of
your freezer box to the bottom of your fridge box. If you do this, you
could run the entire system on one modern, efficient Danfoss compressor.
Holding plates are a stupid system because they are bulky and take up
too much room inside the ice box. Better to have a flat or box-shaped
evaporator and use meats and other dense frozen foods as the holding
plate. What I do is completely fill the freezer part with canned beer.
The Ice beer works best because of the high alcohol content it doesn't
freeze and bust open. But, the thermostat cant' be set to the cold
position. About 1/4 the way to all the way cold works best. My freezer
contains 15 twelve ounce beers. I relpace them one at a time as I drink
them. I maybe drink six on a hot day. I cycle new beers from the fridge
section to the freezer section and add new ones to the fridge section as
I drink them. An admirable holding plate.

My box is very-well insulated and because of it my compressor usually
runs 20 minutes on 40 off in the summer and about 15 minutes on and
close to an hour off in the cooler months of winter. Let's call that
one-third of 24 hours for 8 hours total or 40 amp hours. The box
measures about 1.5 feet by 2 feet by 1.5 feet. For about 4.5 feet cubed.
It and everything else is run by two Evergreen 100 watt photovoltaic
arrays connected to a Sunsie charge controller. The fridge runs more in
the summer months but the days are longer too so the batteries stay
well-charged the year around.


Your system probably has a Danfoss hermetic system and runs about half
of the time, depending on the load, so you actually use about 60
Amp-hours a day. And your fridge/freezer is probably half the size
of mine, and not as cold.

Frankly, I've been thinking that is I did my system today I might use
two modern Danfoss systems, so I could shut down the freezer when not
needed. However, the last time I charged it up I seem to have got it
right and the efficiency is quite high. I curious to see how it works
when we get back into warmer waters in a week.

Like I said above I think you could get away with using one. But your
ice box/fridge would have to be well insulated and close to each other
for it to work well. Most ice boxes are poorly insulated. I know a
fellow who built a 60 catamaran named Shadowfax. Cold molded cedar strip
planking method diagonal layers. Of course he built his own ice box
which was rather largish. He poured one foot of foam all the way around
even on top. He could put fifty pounds of ice blocks in the damned thing
and it would last two weeks. I was amazed. If you have the room, one
foot of insulation all around is the way to go.

Wilbur Hubbard

* Wilbur Hubbard wrote, On 8/10/2007 9:15 PM:
....
However, a 30 Amp draw is quite common for my type of fridge. Its a
1/2 HP motor driving a compressor that feeds several holding plates in
a 9 cu ft fridge and 5 cu ft deep freeze. The actual load varies from
20 to 35 Amps. Here in Maine I've been monitoring it carefully, and
it has taken about 40 Amp-hours per day for the last two weeks. The
fridge stays at 42-46 degrees, the freezer at 15-20, both measured at
the top shelf.

What you're doing is pretty wasteful.

It was installed before the current high efficiency Danfoss unit were
available. However, it still seems more efficient than yours.

Sounds like you have a separate
freezer and refigerator. That's dumb. All you need is a freezer that
connects to your fridge box with a well-insulated duct. Keep your
freezer full of meats and other dense stuff and run it all the time.
Allow some of the excess cold air to migrate into your fridge box by
controlling the size of the duct. The duct should run from the top of
your freezer box to the bottom of your fridge box. If you do this, you
could run the entire system on one modern, efficient Danfoss compressor.

Spill-over systems have some virtue. However, that requires a
particular geometry that can't always be achieved. Also, its rather
doubtful that one Danfoss could chill a system as large as mine. Even
if it could, I would still split it into two. There's a huge
advantage to having redundancy and being able to scale down so a boat
could be left unattended for moderate periods.

Holding plates are a stupid system because they are bulky and take up
too much room inside the ice box.

They take no space at all; their volume is not included!

Better to have a flat or box-shaped
evaporator and use meats and other dense frozen foods as the holding
plate. What I do is completely fill the freezer part with canned beer.
The Ice beer works best because of the high alcohol content it doesn't
freeze and bust open. But, the thermostat cant' be set to the cold
position. About 1/4 the way to all the way cold works best. My freezer
contains 15 twelve ounce beers.

That's a pretty small freezer.

I relpace them one at a time as I drink them. I maybe drink six on a
hot day. I cycle new beers from the fridge
section to the freezer section and add new ones to the fridge section as
I drink them. An admirable holding plate.

In other words, you open the freezer at least six times a day? And
your antifreeze consumption certainly explains the quality of your posts!


My box is very-well insulated and because of it my compressor usually
runs 20 minutes on 40 off in the summer and about 15 minutes on and
close to an hour off in the cooler months of winter. Let's call that
one-third of 24 hours for 8 hours total or 40 amp hours. The box
measures about 1.5 feet by 2 feet by 1.5 feet. For about 4.5 feet cubed.

That's about a third the size of mine combined boxes, which also is
using 40 Amp-hours a day. And the warmest spot in my freezer is 20
degrees. Even in the tropics, serving three people, we rarely went
over 90 Ah a day. And that was before I learned how to maintain it
myself.

It and everything else is run by two Evergreen 100 watt photovoltaic
arrays connected to a Sunsie charge controller. The fridge runs more in
the summer months but the days are longer too so the batteries stay
well-charged the year around.

Adding more solar is high on my priority list.

... If you have the room, one
foot of insulation all around is the way to go.

My freezer has 7 inches all around, including the top. This biggest
issue now is that the seals have degraded, so they now let in too much
humidity. The fridge insulation is more important as you move south
and have higher temperature differentials, and hot nights. My fridge
alone can get by on as little as 15 Ah a day when a cold front comes
through!

On Fri, 10 Aug 2007 21:15:46 -0400, "Wilbur Hubbard"
wrote:


What I do is completely fill the freezer part with canned beer.
The Ice beer works best because of the high alcohol content it doesn't
freeze and bust open. But, the thermostat cant' be set to the cold
position. About 1/4 the way to all the way cold works best. My freezer
contains 15 twelve ounce beers. I relpace them one at a time as I drink
them. I maybe drink six on a hot day. I cycle new beers from the fridge
section to the freezer section and add new ones to the fridge section as
I drink them. An admirable holding plate.

My box is very-well insulated and because of it my compressor usually
runs 20 minutes on 40 off in the summer and about 15 minutes on and
close to an hour off in the cooler months of winter. Let's call that
one-third of 24 hours for 8 hours total or 40 amp hours. The box
measures about 1.5 feet by 2 feet by 1.5 feet. For about 4.5 feet cubed.
It and everything else is run by two Evergreen 100 watt photovoltaic
arrays connected to a Sunsie charge controller. The fridge runs more in
the summer months but the days are longer too so the batteries stay
well-charged the year around.

You're getting down to brass tacks now. My main reason for a fridge
would be to chill beer. I might be out in the Gulf of Mexico and Keys
for a couple weeks at a time. My wife drinks mainly pop and juices,
lukewarm - she doesn't like chilled drinks. I don't care what temp my
water is, but I like my beer cold. I normally don't drink beer in
morning or high sun, but might hanker for a cold Coca-Cola in those
hours, which also comes in 12 ounce cans
I'm thinking for guys like me there is a BCAH calculation for
beer/coke amp hours. I just don't know what it is.
You weren't clear about cooling anything except beer in your reefer.
Let's say I want to spec out reefer cooling 6-8 12 ounce cans per day.
How would you recommend going about calculating BCAH, and sizing the
reefer to accomplish that?
Thanks.

--Vic

* Vic Smith wrote, On 8/11/2007 5:25 PM:
....
I'm thinking for guys like me there is a BCAH calculation for
beer/coke amp hours. I just don't know what it is.
You weren't clear about cooling anything except beer in your reefer.
Let's say I want to spec out reefer cooling 6-8 12 ounce cans per day.
How would you recommend going about calculating BCAH, and sizing the
reefer to accomplish that?

There are books written to address this topic. It runs something like
this:

A BTU is raising a pound of water one degree. If you have a 6-pack,
that's 4.5 pounds of water. Removing heat to bring it from 70 degrees
to 38 means a removal of 144 BTU. Figure 5 BTU of heat removal per
watt-hour of energy in, so we end up with only a cost of 2.5 Amp-hours
to chill the beer.

BUT, what if the beer started at 100 degrees, what if there's two
6-paks, what about the heat losses of the box? These can all be
calculated, but a one cu ft box with 3 inches of insulation will loose
about 1000 BTU per day, and that would cost 16 Amp-hours. Thus, the
total load for a small fridge can be 20 Amp-hours, easily handled by
a small Danfoss like the BD35.

One point here is the the fridge could be a lot larger - you could go
to 4 cu ft and still have a loss of only 2000 BTU. Or, if you put in
6" of foam you can keep the loss down to 1200 BTU on a 3 foot box.
(These numbers from a table by Grunert.) Also, the "cool down" cost
can be estimated just by considering the weight of the food/drink
consumed each day. Since this is largely liquid (beer/coke/water)
keeping a little bit of butter or cheese cold costs very little. Once
you're in for the basic investment, there's little additional cost to
keeping some eggs, and maybe some bacon, etc, since they get added
cold at the start.

Contrary to the "common wisdom" opening the door is not a major cost,
the heat content of the air that comes out is rather low. You can
even make the case that digging around in a top-loader creates more of
a loss than quickly opening the door of a front loader.

What it comes down to is the cost of chilling your favorite beverage,
and the heat loss of the box itself.

On Sat, 11 Aug 2007 19:56:22 -0400, Jeff wrote:

* Vic Smith wrote, On 8/11/2007 5:25 PM:
...
I'm thinking for guys like me there is a BCAH calculation for
beer/coke amp hours. I just don't know what it is.
You weren't clear about cooling anything except beer in your reefer.
Let's say I want to spec out reefer cooling 6-8 12 ounce cans per day.
How would you recommend going about calculating BCAH, and sizing the
reefer to accomplish that?

There are books written to address this topic. It runs something like
this:

A BTU is raising a pound of water one degree. If you have a 6-pack,
that's 4.5 pounds of water. Removing heat to bring it from 70 degrees
to 38 means a removal of 144 BTU. Figure 5 BTU of heat removal per
watt-hour of energy in, so we end up with only a cost of 2.5 Amp-hours
to chill the beer.

BUT, what if the beer started at 100 degrees, what if there's two
6-paks, what about the heat losses of the box? These can all be
calculated, but a one cu ft box with 3 inches of insulation will loose
about 1000 BTU per day, and that would cost 16 Amp-hours. Thus, the
total load for a small fridge can be 20 Amp-hours, easily handled by
a small Danfoss like the BD35.

One point here is the the fridge could be a lot larger - you could go
to 4 cu ft and still have a loss of only 2000 BTU. Or, if you put in
6" of foam you can keep the loss down to 1200 BTU on a 3 foot box.
(These numbers from a table by Grunert.) Also, the "cool down" cost
can be estimated just by considering the weight of the food/drink
consumed each day. Since this is largely liquid (beer/coke/water)
keeping a little bit of butter or cheese cold costs very little. Once
you're in for the basic investment, there's little additional cost to
keeping some eggs, and maybe some bacon, etc, since they get added
cold at the start.

Contrary to the "common wisdom" opening the door is not a major cost,
the heat content of the air that comes out is rather low. You can
even make the case that digging around in a top-loader creates more of
a loss than quickly opening the door of a front loader.

What it comes down to is the cost of chilling your favorite beverage,
and the heat loss of the box itself.

Thanks, Jeff. You've given me a great starting point.
Forgot my BTU's, probably because I always used them in steam calcs.

--Vic

"Vic Smith" wrote in message
...
On Fri, 10 Aug 2007 21:15:46 -0400, "Wilbur Hubbard"
wrote:


What I do is completely fill the freezer part with canned beer.
The Ice beer works best because of the high alcohol content it doesn't
freeze and bust open. But, the thermostat cant' be set to the cold
position. About 1/4 the way to all the way cold works best. My freezer
contains 15 twelve ounce beers. I relpace them one at a time as I
drink
them. I maybe drink six on a hot day. I cycle new beers from the
fridge
section to the freezer section and add new ones to the fridge section
as
I drink them. An admirable holding plate.

My box is very-well insulated and because of it my compressor usually
runs 20 minutes on 40 off in the summer and about 15 minutes on and
close to an hour off in the cooler months of winter. Let's call that
one-third of 24 hours for 8 hours total or 40 amp hours. The box
measures about 1.5 feet by 2 feet by 1.5 feet. For about 4.5 feet
cubed.
It and everything else is run by two Evergreen 100 watt photovoltaic
arrays connected to a Sunsie charge controller. The fridge runs more
in
the summer months but the days are longer too so the batteries stay
well-charged the year around.

You're getting down to brass tacks now. My main reason for a fridge
would be to chill beer. I might be out in the Gulf of Mexico and Keys
for a couple weeks at a time. My wife drinks mainly pop and juices,
lukewarm - she doesn't like chilled drinks. I don't care what temp my
water is, but I like my beer cold. I normally don't drink beer in
morning or high sun, but might hanker for a cold Coca-Cola in those
hours, which also comes in 12 ounce cans
I'm thinking for guys like me there is a BCAH calculation for
beer/coke amp hours. I just don't know what it is.
You weren't clear about cooling anything except beer in your reefer.
Let's say I want to spec out reefer cooling 6-8 12 ounce cans per day.
How would you recommend going about calculating BCAH, and sizing the
reefer to accomplish that?
Thanks.

--Vic

Beer and pop is VERY expensive in the Bahamas and so is ice. The last
time I cruised the Abacos I brought along 20 twelve packs of beer and 20
twelve packs of cheap pop of different flavors. All in 12 ounce cans. I
stored them on the sole of the head stacked to the level of the v-berth
with a layer on the sole of the main salon. I had all I wanted to drink
cold beverages lasting three months. My Adler Barbour air cooled
compressor kept the beers almost frozen cold. I like them to be sort of
slushy when the top is popped.

This is what I've got for a compressor
http://www.waecousa.com/page.aspx?p=thecold

And this is the evaporator: http://www.waecousa.com/page.aspx?p=theevap
The top one, the VD 150.

With a 12pack in the freezer and two twelve packs lining the bottom of
the icebox that makes one freezing cold 12pack and two cold 12packs. As
I drink several beers or pops from the freezer I add more from the
icebox and add warm ones from the sole into the bottom of the ice box.
There's room for cheese, fruit, veggies, eggs, meats and other things
that are best kept cold on top of the drinks in the bottom of the box.
Butter I don't care if it melts a little. I use tinned butter from New
Zealand when I'm in the Bahamas. It's cheaper than butter in the states.

Two 100 watt solar panels atop the bimini provide all the juice I need
for the fridge and everything else. One thing though. A couple or three
cloudy days in a row means I shut the fridge off at night. The contents
keep cold all night long and when the sun comes out I turn it back on.
It runs a little longer on the first couple of cycles but the solar
panels alone are more than enough to run it so the excess goes into the
batteries. I carry an old 600 watt portable Yamaha gasoline generator
for emergencies but I haven't needed it for years and years.

To avoid the initial btu use trying to cool down three warm 12pack, buy
cold 12packs from the supermarket fridge. Surprising cold or warm the
price is the same. That way you load your box up with cold drinks from
the very start and save that initial surge of energy being used. Also
buy a frozen chicken whole and put it into the ice box. It will stay
frozen for two days and help keep your other stuff even colder. When it
thaws out then you can cook it and eat it. You can do this with steaks
too. Surprising frozen steaks and chicken are not that overpriced in the
Bahamas.

You're right on about the cold beers. Nothing hits the spot better. The
only trouble is you've got to be diligent and ration them out or you'll
find yourself going through a 12pack a day which isn't good at all.

Wilbur Hubbard

On Aug 11, 6:11 pm, "Wilbur Hubbard"
wrote:

You're right on about the cold beers. Nothing hits the spot better. The
only trouble is you've got to be diligent and ration them out or you'll
find yourself going through a 12pack a day which isn't good at all.

Wilbur Hubbard- Hide quoted text -


Wilbur I must protest and challenge your claim to manlyness. I
proclaim anyone who uses a refer a fu-fu girlie man. I simply find the
local brew and serve at room temp. Why, cause poor peole dont have
refers at home and still neeed to drink somthing. So buy what the
local poor people drink. My favorite was in Fiji. Ahhh, Fiji Bitter
served at 83 degrees F. Now that was a fine brew. So to all thoes
girlie boys out there who whine cause their beer is warm I say, fluff
n nutter! Git a grip and a good warm beer! Then ya dont have all thoes
problmes ole Skip is having trying to charge a 1000 Ah house bank.
Bob