Fridges

Boater123

Looking at fitting a new fridge to be powered off batteries only and was wondering:

In terms of power consumption is a 12v marine fridge better or worse than a modern domestic 220v fridge run through a suitable inverter?

I have a modern 80L 12v Marine fridge with small ice box that uses 48w, so 48w over 12v equals 4 amps per hour drain on the batteries?

Just saw a new fridge with small freezer in a showroom that uses 100w, so 100w over 220v by a 75% efficiency factor for the inverter is around 0.6 amps per hour?

I am correct in these calculations, or am I completely missing something? (Which wouldn't be the first time);)

Pete67

The marine fridge consumes 48 watts. The domestic fridge consumes 100 watts Those figures do not change based on the supply voltage, that is the power required to run each fridge.

The marine fridge running on the batteries at 12 V will draw 4 amps continuously. The mains fridge will draw 100w from the invertor, the invertor will have to draw at least 100w from the batteries, in fact slightly more to allow for inefficiencies so say it's 120W. At 12 volts that's 10 amps continuously.

spaceHopper

Get a good 12V power fridge, you can't use a domestic fridge it's not made to move in the way it would in a boat. If you have well insulated top loader fridge/cooler then it will stay cold. With a fridge door when you open it all the cold air spills out, with a top loader it will stay in.
If you freeze a bottle of water you have a good cold bank to keep things cold and can switch off the power for while.

Steve

What kind of boat?

If you are careful and only run the fridge with engine on then happy days. I wouldn't run it from battery ever.

sogood

I wanted to replace the (missing) fridge on my latest boat. Rather than paying silly money for something that didn't quite justify the expense, I came across an electric cooler box in Lidl that cost around €50. I only wanted something to keep milk cool/fresh in and maybe the odd bottle of water and some food stuffs.

The one I got works on 12V and on mains also. It is a top opening with a carry handle and can be "charged up" at home on mains, before bringing it on board.

I used the original space on the boat to house the cooler and you can see pics on my thread " Let the games commence". Depending on the sort of standard you want it's a worthwhile consideration.

spaceHopper

sogood wrote: »

I wanted to replace the (missing) fridge on my latest boat. Rather than paying silly money for something that didn't quite justify the expense, I came across an electric cooler box in Lidl that cost around €50. I only wanted something to keep milk cool/fresh in and maybe the odd bottle of water and some food stuffs.

The one I got works on 12V and on mains also. It is a top opening with a carry handle and can be "charged up" at home on mains, before bringing it on board.

I used the original space on the boat to house the cooler and you can see pics on my thread " Let the games commence". Depending on the sort of standard you want it's a worthwhile consideration.

With out plugging in the one I got in Lidl will keep ice frozen for two days, put bottle of water in the freezer and you'll hardly need to plug in.

Corbally

I think it's important to figure out how you are going to use it. If it's to keep milk cold for one night every other weekend the €50 Lidl job would be the cheapest option. Freeze a few freezer blocks at home to start it off and only use it when the engine is running.
If you are going to be using the fridge for meat etc for long period of times then you need to get it right. Your batteries will be the limiting factor so start with finding out how much usable power you have for the fridge. 1 100ah battery won't run a 100w fridge for very long.

fergal.b

One for sale on DD https://www.donedeal.ie/boatextras-for-sale/electrolux-dometic-gas-12v-220v-60lt-fridge/14411045






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