"Eisboch" wrote in message
...

"Chuck Gould" wrote in message
ups.com...

On Nov 7, 5:20?pm, "Eisboch" wrote:
"Chuck Gould" wrote in message

If you're running a genset or hooked to shorepower, you can easily
power a 30-amp converter. Let's say your converter is divided into two
legs, with 15-amps per side for the house and starting batteries. The
converter will easily replace any of the energy used by the
refrigerator at a rate that is as fast or faster than the refrigerator
draws it down. I would be at least slightly surprised to learn that
you use only 110-volt lightbulbs, etc etc while underway to avoid
draining the battery. If the compressor runs 15-20 minutes per hour,
it's using relatively little DC as well and you're simply running on
the "top" of the battery.

It's been years since I had AC power to my refrigerator freezer, and
my current batteries are about five years old and still going very,
very strong.


My setup is a little bigger than your example, but your point is valid.
The problem with running a large refrig on batteries is that if you happen
to lose shore power for a day or two in your absence, your battery or
batteries (depending on your setup) is toast. On a couple of occasions
I've arrived at the boat only to find that a overnight guest in the next
slip inadvertantly shut the circuit breaker off on the pedestal for my
boat.

I'd rather replace what little was in the refrig than have to prematurely
replace those big honkin' batteries again.

Oh ... mine are going on 6 years and still are very strong. The original
batteries were replaced after two years of service, mainly because they
were allowed to go dry and would not recharge fully (boat was in Florida).

Eisboch


Running a small refrig on batteries sux also. Before I put an isolator
between the truck and the camper, I forgot to switch from DC to propane when
overnighting at a state campground without power. Killed both the camper
battery and both the batteries in my diesel truck. After a couple hours AAA
got there to give us a jump. And my Refer / Freezer is about 3 cubic foot.

Eisboch wrote:
"Chuck Gould" wrote in message
oups.com...
On Nov 7, 2:47?pm, Jim wrote:
My Norcold DF0704 stopped working on 110. Seems to work fine on 12
volt. It was probably original with the boat, so it must be 20 years
old.

Replace or repair?

It looks like that model isn't made any more and what I see (on a very
quick look) shows that none of the new ones fit the cutout.

Maybe i just haven't found the right one yet.

What have you all done?

Thanks

Here's a possible surprise for you- your Norcold never ran on 110
volts.

Your compressor etc runs on 9-volts DC. There is a step down
transformer to convert the 110 AC to 9 volts DC. There is another to
step down to 9 volts on the DC side.

There is really no reason to run your fridge on AC. If you have AC
available, (either from shorepower or an onboard generator) you can
recharge the battery faster than the fridge will draw it down.

When we replaced our little 6 cu ft fridge a few years ago I saved a
couple of hundred bucks by not getting the AC/DC model and going DC
only......as that's the way those units all work, anyway.


I think differently. I'd rather run it on 120 vac when dockside and take
that load off the batteries and charger. In fact, while underway I almost
always run the genset as well, so the refrig rarely, if ever, runs off the
batteries. Depending on the size, the refrig can represent quite a large
load amp wise at 12 vdc. I am of the school that batteries life is affected
by high charge/discharge rates.

No particular scientific reason .... I just believe that.

Eisboch




I am positive if you allow your batteries to completely discharge it
will reduce their life. Don't ask me how I know this.