Any alternative to electric fridge costs

[RupertW]

We have a slightly odd set up electrically on our boat which we keep in Croatia with minimal electrical needs. I haven't even bought a regulator or improved on the 2x80Ah old domestic batteries although we spend most of our holidays at anchor.

There are a couple of short term reasons for low electrical usage (auto helm continuously rebuilt so no overnight trips so no need for night lights) and one longer term one which is that the fridge compressor is belt driven directly from the engine.

This is very efficient compared to alternator->battery->electric motor->compressor but does have a couple of distinct disadvantages, that we can't get the fridge cold in the Marina when stocking up for a day before setting off, and we have to run the engine for at least an hour once or twice a day depending on the heat, which is a bit antisocial if we are in a quiet anchorage or annoying if our daysail is only a couple of hours long and there's a decent breeze.

I certainly don't want to lose the current arrangement but I would like to add to it.

So, any thoughts about another way to cool the fridge using 12v? The only suggestion made so far by a local mechanic is to fit the full electric equivalent as well which would give us two plates inside the fridge and cost quite a lot for a second compressor etc.?

 

[Jean]

But a 12 volt electrical compressor is likely to discharge an 80 amp hour battery in a few days, even without any other loads on it, then it’s back to running the engine again to charge it up, so no real gain.

 

[RupertW]

But a 12 volt electrical compressor is likely to discharge an 80 amp hour battery in a few days, even without any other loads on it, then it’s back to running the engine again to charge it up, so no real gain.

You're right but we have a biggish Bimini which would take a couple of large flexible solar panels - no need or point at the moment but it's an option if our electrical needs increase as there are many cloudless days.

 

[blackbeard]

Quick'n'dirty solution at no cost.
Some time, when you would be running the engine anyway, put food in insulated box or bag or some kind, fill 'fridge (not too full, allow room for expansion as water freezes) with plastic bottles not-quite-full of water, set to freeze hard, put bottles of resulting ice in cool bag with food, should be a couple of days before you need to run fridge again

may be enough to keep butter/milk/beer cool

 

[mawm]

<i>we can't get the fridge cold in the Marina when stocking up for a day before setting off, and we have to run the engine for at least an hour once or twice a day</i>

Get it serviced!

I used to have to run mine twice a day for 40 min. Since I had it serviced it freezes everything in about 20 min. Now I run it twice a day for 10 - 15min……..but I still have to charge the batteries from the engine…….

 

[RupertW]

<i>we can't get the fridge cold in the Marina when stocking up for a day before setting off, and we have to run the engine for at least an hour once or twice a day</i>

Get it serviced!

I used to have to run mine twice a day for 40 min. Since I had it serviced it freezes everything in about 20 min. Now I run it twice a day for 10 - 15min……..but I still have to charge the batteries from the engine…….

Interesting - we did have it fixed when we bought the boat 18 months ago but I wonder whether that was just a quick bodge. It's quite a large fridge though and the weather is often well into the 30s bit well worth checking. Thanks

 

[Billjratt]

....... It's quite a large fridge though and the weather is often well into the 30s...

If it's really big, make sure the insulation is equally massive, and if it gets a bit empty, fill the space by storing something like spare kitchen rolls in there to minimise the amount of air you're trying to cool.
I hope the boat is white. We had to hang a section of white canvas over the side of our dark-hulled boat to stop the fridge-works getting heated up by the sun!

 

[RupertW]

If it's really big, make sure the insulation is equally massive, and if it gets a bit empty, fill the space by storing something like spare kitchen rolls in there to minimise the amount of air you're trying to cool.
I hope the boat is white. We had to hang a section of white canvas over the side of our dark-hulled boat to stop the fridge-works getting heated up by the sun!

White hull, White decks - a bit boring looking as I slowly take off the horrible bits of trim and clean the old rust, oil and black rubber stains. Not sure I want to fancy it up too much, though.

Am definitely thinking of a wide awning anyway and saw a lovely one last year that went from the forestay round the mast, under the boom and back to the bimini, and was wider than the boat once aft of the stays. Probably next year when we fully get over the novelty of almost continuous sunshine.