Something does not sound right here. my adler barbour air cooled refer pulls 60 amps in a 24hr period in the hottest months on the chesapeake. With two group 31 batteries i have about a 210 amp hour capacity. never running below 50% depth of discharge gives me 100 ah to work with. the refer takes 60 leaving me with 40 for everything else. i have never pulled more than 75-80 total in a 24hr period. i think:
1. your batteries are not in very good shape
2. you dont have a battery monitor and dont really know how much juice the refer is pulling.
3. something is wrong with your refer.
4. You have dirty or corroded connections somewhere causing a lot of resistance.
5. SOme combination of all of the above?
For sure there are more efficient units available now but the old air cooled alderbarbour is not that bad. I'm sticking with mine until it dies. w. 12v danfoss compressors are the way to go. (quote/)
I have to agree with Ted here. My old A-B Cold Machine (Danfoss 2.5) still runs great. I may soon have to replace the evaporator but I'll do that when it gets too corroded to stand the sight of it in the fridge. The newer units may be more efficient but they are also less reliable.
I think you're asking for trouble when you mix salt water cooling with electrical stuff so I think air cooled is the way to go. The keel cooler might be ok but I can't recommend the water cooled condenser system.
We use ours in Florida and the Bahamas. We run it 24/7 when we cruise and it makes ice for my rum. The fan recently quit on mine so I replaced it with two 12v muffin fans. One blowing through the condenser and the other aimed at the control box.
Our house bank batteries are currently 10 years old. They are two Prevailer (German made) gel cells. I think they are about 200 or maybe 220 amp hours total. I can't find them listed in the catalog but they measure about 13x13x10 ... I thought they were Group 31s but the measurements don't jibe. I may replace them soon but it'll likely be with two GC-2 6 volt batteries ($74 each at Sam's Club). I'm thinking about adding two more and a 100 amp alternator but I need to resolve the belt drive issue first.
Anyway, we have a Kyocera 120 watt solar panel and that provides sufficient power in daylight but over night we run about 50 to 70 amp hour deficit which we make up by running the engine an hour or two. The fridge itself appears to use about 5amps when the compressor kicks in and less than one when it cycles. Even if the compressor ran all the time it would only run 120 amp hours so I would agree with Ted and the idea that maybe your system needs a tune up.
I'd suggest you start with
Richard Kollman's forums or his
Website Home Page. He has a wealth of info there ...
I would also recommend that anyone thinking of an extended cruise, even if it's only down into the Caribbean or Mexico, get real familiar with the workings of your refrigeration system and be prepared to deal with issues yourself. These systems are pretty simple and anyone with average McGiver skills should be able to fix them. Get Richard's Books to start with.
It's hard to beat cruising your boat and kicking back with ice clinking in the glass as you watch the sunset from your cockpit, one arm around your better half... Seems to make all the effort worth it.