I removed the ice maker in the cockpit that was not functioning on my Sundancer. I'm replacing it with a mini fridge that draws 1.5 amps at 120 volts. (180W) My plan is to bring a line up from the house batteries that are in parallel and feed a AC inverter to run the refrigerator on 120 volts off the batteries. If I do not leave my converter on in the boat for a week or so, will this load drain my house batteries? I think the other option would be to wire the inverter through a relay so that when I'm on Dock power, the fridge runs on 120 volts and when the power is lost, the relay kicks over and only then will it run off the batteries.
Running cockpit fridge on house batteries.
- Thread starter MJPesky
- Start date
Mark.60
Well-Known Member
Why not just replace it with an AC/DC fridge and not have to go the inverter route ?
Stee6043
Well-Known Member
To do the actual math you'd need to provide the amp-hour capacity and quantity of your house batteries. I'd imagine the expected efficiency of your inverter also matters.
That said, running an AC fridge off your house batteries for a week at a time sounds very much like a long shot. Especially if you're in a hot climate.
You may want to start researching solar or wind chargers for your boat if you need to go a week between plugging in with the expectation of having cold beers onboard when you do arrive...
That said, running an AC fridge off your house batteries for a week at a time sounds very much like a long shot. Especially if you're in a hot climate.
You may want to start researching solar or wind chargers for your boat if you need to go a week between plugging in with the expectation of having cold beers onboard when you do arrive...
BlueYonder
Active Member
How large is your house battery bank? If that fridge runs 50% of the time, you are looking at a draw of around 7.5 amps DC per hour. Without a charger running, that draw will kill your average house bank pretty quickly.
You need an inverter with an automatic switch. Your inverter will pass through AC power when on shorepower, then invert off the house bank when disconnected from shorepower. Leave the charger on anytime you are at the dock.
You need an inverter with an automatic switch. Your inverter will pass through AC power when on shorepower, then invert off the house bank when disconnected from shorepower. Leave the charger on anytime you are at the dock.
Mark.60
Well-Known Member
Sometimes you get what you pay for.
I have a small Norcold fridge/freezer in the cockpit and the beer is always cold. We spend a lot of time on the hook and the only problem is the fridge is not self stocking
I have a small Norcold fridge/freezer in the cockpit and the beer is always cold. We spend a lot of time on the hook and the only problem is the fridge is not self stocking
I'm on shore power 90% of the time, so I think that's my answer. Keep it on 120v power at the dock or on genny, and install a relay with the power to the coil paralleled off the 120v so the coil power drops out when disconnected and will then provide 120v power from the battery and inverter.
- Apr 10, 2021
- 997
- Boat Info
- 1999 Sea Ray 290 DA
- Engines
- Twin 4.3 with Alpha 1 Gen 2 drives
LMAO Mark, My fridge has the exact same problem!
Sundancer
Well-Known Member
- Jul 20, 2005
- 2,909
- Boat Info
- 34 year old CLASSIC 300 DA, towed almost anywhere behind the Duramax Dually Crew Cab.
- Engines
- 16 cyl, 700 cu. in./Alpha I's
I added 2 100-watt panels and an mppt controller prior to a week-long trip last Summer. The panels kept the two-house batteries charged on a daily basis. I was running the old original Norcold from 1989 that has a pretty lame gasket so it runs a little more than it should too! I think it stats 5 amp or so? I love not having to worry about the house batteries state of charge knowing I can crank the fridge DOWN during the day to make some ice! I can charge phones, run the stereo and not worry about their status. We stopped Saturday night and started the boat again Thursday to dump the head. I won't even take the generator anymore and I could go also summer and never start it now!
MoonRiver
Active Member
where did you place the panels?
Sundancer
Well-Known Member
- Jul 20, 2005
- 2,909
- Boat Info
- 34 year old CLASSIC 300 DA, towed almost anywhere behind the Duramax Dually Crew Cab.
- Engines
- 16 cyl, 700 cu. in./Alpha I's
I had them sitting on top of the bimini. I tied them up there but have rare earth magnets a friend of mine suggested. I'll be switching to those this year! Mine are temporary and I don't leave them up all the time. I opted for the flexible panels which won't last as long as a hard panel, but they take up very little space when not used and that was a big factor!!
