Refrigerator Question

Hi All,

Going on a 5 day boating excursion around Catalina Island, CA. To add to our refrigerator needs, I was thinking of bringing on board a small 4.4 cu ft Energy Star rated refrigerator (110 ac) and running it off the inverter.

I currently have three 4-D house batteries at approximately 200 AH per battery. Per label, the refrig uses 1.1 amps.

I can run the generator during the day to top off the batteries, but at night it will be all batteries. I would like any feed back, negative or positive regarding this idea.

Thanks, Chris

Chris, you are going to do exactly what I currently do. My old original 1981 fridge is an energy hog so I put in a 110V on a 1000W inverter. I can stop at 2 in the afternoon and run it all night on 4 x 6v x 228 ah batteries and only use 10% of the batteries energy. I do use a very efficient cooler for drinks so we are not in and out of the fridge constantly just for drinks.

Wow! That's pretty good.

It works, not figuring any inverter loss you will use aprox 13 amps for every hour your refer runs, assume worse case 50% duty cycle. During a 12 hour period the refer would use about 25% of the available 300 useful amp/hours in your battery bank...

Thanks

I run like that on my boat with my second fridge secured to the countertop. I have a 1000W inverter that runs the 3 cu ft (or so) dorm fridge. (It actually was the dorm fridge for both my daughters!) It costs a lot of AH per day, but if you have daily engine runs or genset runs, you should be OK. Do you have a battery SOC meter?

When the food thins out, perhaps you can consolidate into one fridge so maybe you won't have to operate it the whole trip.

Thanks for the feedback Al. I do have SOC meters and the inverter has an auto disconnect when the batteries drop down to 11.6 v.

I just came off a week spent over at Two Harbors Catalina. I run one 8D AGM on a 2000 watt inverter and power two 110V Refrigerator / Freezers and a ULINE 110V icemaker. I would typically go 8 hours between charging but could easily power through the night and that included running a TV / Satellite receiver for a few hours.

Just run the genset when powering the high demand items like stove / microwave or Keurig and charge during those times as well.

Two important techniques for keeping refers cold and using little power.

1) fill the freezer with water to freeze or frozen food. Cold water jugs in the refer part
help as well.
2) dont open the door. Store frequently accessed stuff with some ice in an ice chest.

TG, thanks for the response. Two of the five days will be in Two Harbors (Cat Harbor & Isthmus).

Bayview, good tips. I was planning on using an ice chest for water & soda to keep the door shut as much as possible, but the beer has to stay cold, so that has to stay in the refrigerator.

Adding salt to the water , or simply freezing sea water will help the box stay COLDER


It will not make the box stay cold LONGER as the salt takes up volume that could be water..

Here is my solution for extra fridge and freezer space aboard, it is a ARB 12/24 or AC powered 63 quart unit. The reviews I read everyone was happy with it, it is very well built and marketed to off-road 4x4 enthusiasts.
ARB Fridge Freezer 63 Quart Bundle with ARB Wireless Fridge Remote Display 10800602RM https://www.amazon.com/dp/B01JH85FD2/ref=cm_sw_r_cp_api_9jz3xbZJ9W779

I have two banks of 2 8D batteries each and a Magnum inverter setup that supplies 120/240 ac. I can run a large double door reefer, a small freezer, my Incinolet toilet, and almost all lights for about 48 hours. Only 12v lights are emergency and running/anchor lights.

Some numbers to keep in mind, if the fridge uses 1.1 amps at 120V, that's 132 watts. 132 watts means the inverter would be drawing 11 amps from the batteries at 12V, but since no inverter is better than 90% efficient, it will actually be around 12 amps from the batteries. If the fridge runs 50% of the time, thats 6 amp hours taken from the batteries per hr of use. If you have 600 amp hours of batteries (3 x 200), then you could run that setup for 100 hrs before the batteries were at 50% capacity - which is regarded as far as batteries should be drawn down on a regular basis for a decent lifespan. If the fridge runs more or less and/or you have other things running it would obviously impact the numbers.

Ken