Running a 'Dorm fridge' without an electric hookup?

[ScouterMom]

I'm not really interested in running electronics - tv's, microwaves, etc - but I sure do hate the replacing bags and bags of ice, getting everything wet & draining the coolers - esp in 90 degree weather! this past weekend, even with good coolers, we had to buy ice every day.

What would I need to do to run my med size 'dorm fridge' ( NOT a camping /propane fridge) on a car or RV battery?

my '73 starcraft has a 'converter' but I have never used it.  We Have plugged in when we have campsites with power - and everything works - but there has never been a battery hooked up to the system.

On the plus side, we got rid of the old style propane tanks, hooked up a new dual regulator and hoses, (tested all connections for leaks) and the stove started right off for the first time this weekend.  We were thrilled to have an easy way to make coffee and cook breakfast without a fire or tiny backpacking stove!  We haven't tried the furnace yet - since we plan to replace the linoleum, we figured we would wait on that until we take out the cabinets, clean it up really well, and then try it.  We certainly did NOT need a furnace this past weekend!  

Laura

[paul33329]

I've got the same question, except I have a battery already for lights.  My 78 jayco has an ice box, which as far as I can tell are useless.  I could fit alot more in a cooler.  Thinking of replacing it with a 1.7 Cu feet, 20 inch high fridge.  A 3-way fridge is cost prohibitive right now.  A friend told me his three way fridge ran his battery down in about 8 hours when he didn't switch to propane during a drive.  Is it really that bad and would a basic fridge plugged into an outlet running off the battery last any longer?

There was a calculating thing in one of these forums yesterday and now I can't find it.  You could enter the amp hours and it would calculate how long your battery would last.  Does anyone know where that went?

[AustinBoston]

The biggest deep-cycle batteries you can practically put on a pop-up will only run a fridge for a few hours before going dead.

If you really need a fridge and don't want to pay for one that can run on propane, then you will need either 1) a generator that will need to run continuously, or 2) An electric site.

A better solution to the "bags and bags of ice" is to do ALL of the following:

• Use an extreme cooler (both Coleman and Igloo make them).
• Keep it out of the sun and the wind.  Remember, the sun moves over the course of the day.  It has to stay out of the sun all day, not just in the morning when you leave the campsite.
  
• Don't leave it directly on the ground.
• Drain the water from it at least once a day.
• Freeze everything before packing it.
• Keep the kids out of it.  Opening it 50 times a day for another pop is a killer.  If this is a problem, bring a second cooler just for the drinks.
• Use a combination of block ice and cube ice.  Cube ice is good for cooling things off fast, but block ice has a holding power that cube ice can't match.

Doing all of these things will keep it cold *at least* five days in 95

[wavery]

You could do it but you would need the following:

1. 4-series 31, deep cycle batteries (minimum). (approx $500)
2. 2000w inverter. ( change 12v DC to 115v AC). (approx $500)
3. A 2500w generator that would run all day to run the fridge plus a 25A battery charger to charge the batteries to run the fridge at night (during quiet hours). ($1400 for a quiet generator or $500 for a loud one, plus about $10 a day for gas). If you get the loud one....add about $600 for deffensive weapons :p .

Total investment approx $2,500. You may want to consider looking into a propane fridge.

[TheViking]

You could do it but you would need the following:
 
1. 4-series 31, deep cycle batteries (minimum). (approx $500)
2. 2000w inverter. ( change 12v DC to 115v AC). (approx $500)
3. A 2500w generator that would run all day to run the fridge plus a 25A battery charger to charge the batteries to run the fridge at night (during quiet hours). ($1400 for a quiet generator or $500 for a loud one, plus about $10 a day for gas). If you get the loud one....add about $600 for deffensive weapons :p .
 
Total investment approx $2,500. You may want to consider looking into a propane fridge.

Having a Dorm fridge in your pop-up............Priceless

[curryp]

Can't help you with the fridge question. But as far as making ice last in the cooler. I bought one of the space blankets from Cabelas and use it to cover the coolers during the day. I used an extreme cooler in three days of 90 degree heat and put much of the items in frozen. Some of the stuff that I didn't put in frozen did freeze because the cooler was cold.

The amp calculator can be found at http://trucks.pcwize.com/dc_configurator.php

I liked it so much I bookmarked it.

[brainpause]

Several people have implied it, but not said it directly:

Your 110volt dorm fridge will not work when plugged into an outlet, but your camper isn't plugged in to anything. The battery is for 12V accessories only, such as lights, and things of that nature.

That's the reason wavery suggested the inverter (NOT converter) and big batteries. With that setup, it would run the dorm fridge, but for a short time only.

Larry

[paul33329]

That's an interesting explination brainpause.  I did not mention that I have an inverter.  I've plugger into external power and turned the lights on.  With the external power turned off the lights still come on through the battery and inverter.  I don't really understand how this all works I guess.  I thought all popups had inverters so I didn't mention it.  So I should be able to plug in a fridge with battery power with the inverter I think.  although I guess I won't so I don't kill the battery.

[wavery]

That's an interesting explination brainpause.  I did not mention that I have an inverter.  I've plugger into external power and turned the lights on.  With the external power turned off the lights still come on through the battery and inverter.  I don't really understand how this all works I guess.  I thought all popups had inverters so I didn't mention it.  So I should be able to plug in a fridge with battery power with the inverter I think.  although I guess I won't so I don't kill the battery.

What you have is a "Converter" (converts 110v AC current to 12v DC current)

An "Inverter" converts 12v DC current to 110v AC current. Which is what you would need to run a 110v dorm fridge from your camper's batteries.

[AustinBoston]

That's an interesting explination brainpause.  I did not mention that I have an inverter.  I've plugger into external power and turned the lights on.  With the external power turned off the lights still come on through the battery and inverter.  I don't really understand how this all works I guess.  I thought all popups had inverters so I didn't mention it.  So I should be able to plug in a fridge with battery power with the inverter I think.  although I guess I won't so I don't kill the battery.

I think you may be confused about the difference between a CONverter and an INverter.  It is a common mixup.

Nearly all pop-ups are equipped with a CONverter; it turns 120 volts AC (house current) into 12 volts DC (battery power).  Depending on your converter, it may charge the battery, serve as the 120V breaker box, and automatically switch between 12V converter power and 12V battery power.  This is what runs the built-in lights in your pop-up.

I have never heard of a pop-up that came from the factory with an INverter.  Inverters change 12 volts DC into 120 volts AC.  Inverters typically have one or more outlets directly in the device itself.

Austin

[kampingkoge]

You could do it but you would need the following:

1. 4-series 31, deep cycle batteries (minimum). (approx $500)
2. 2000w inverter. ( change 12v DC to 115v AC). (approx $500)
3. A 2500w generator that would run all day to run the fridge plus a 25A battery charger to charge the batteries to run the fridge at night (during quiet hours). ($1400 for a quiet generator or $500 for a loud one, plus about $10 a day for gas). If you get the loud one....add about $600 for deffensive weapons :p .

Total investment approx $2,500. You may want to consider looking into a propane fridge.

I just picked up a 1.7cu dorm fridge from sears and used it this past weekend.  The amp rating on this fridge's compressor is only .8amps.  My e2000 Honda generator on economy mode did not require any additional power (increased engine RPMs).  I also ran it on one of the portable battery jump start units that have a built in inverter during the evening and the display only register 50 watts continuously after the initial startup which I believe was about 75watts for a second or two. This only lasted 2 hours so I figured with a true deep cycle it would last through the night.  As a side note the little dorm fridges with compressors are being phased out for the new "thermo electric" fridges which imho are junk.  They are only meant to cool up to 30 degrees below the outside temp and are not recommended for garages or outside use.  The one I bought from Sears was actually the display model from a closeout sale as they were no longer going to sell the compressor dorm fridges.

I was thinking about pulling my 3 way fridge out of the camper and sliding this in its place.  I have never ran the 3 way on propane or 12 volts, usually it is used only for dry storage as it just does not get cold enough. .... any thoughts?   Manual says 1 inch clearance is required on the sides and 4 inches in the back.

[zillaq]

I did some digging and came up with perhaps some useful information.  Depending on the size of your dorm/compact refrigerator you might be able to get away with running it for a half day on a cheap 400 watt to 500 watt inverter and a group 27 battery.  You would have to charge the battery after 12 hours.

A little 1.7 cu ft. refrigerator draws .7 amps at 120vac.  That works out to be about 85 watts.  If your inverter is 90% efficient that computes out to about 7 amps at 12 vdc from your battery.  From the Interstate battery website I got data for their SRM-27.  It will make 5 amps for 17 hours.

A little Honda EU-1000 generator makes plenty of power for a small refrigerator such as the Sanyo.  It would use about .6 gal of gas per 8 hours at 1/4 load.  Price is around $750.  It would also charge your battery.

A propane refrigerator installed - cost?
$750 buys a lot of ice.

[tplife]

We use one cooler for dry ice and frozen meats and thaw each day as we need them.  The other cooler is for wet ice for thawed stuff and drinks.  Dry ice is the only way to go for us for extended dry camping.

[fleagalbaum]

All this talk about fridges..... after reading about all the bad experiences I was leary about using my fridge.  My 19month  old son is dependant on growth hormone, I needed to bring a supply for 2 weeks. so we decided to use the dometic 2010(?)  not sure right now.   fridge that came with my '94 jayco 1207

anyways I found a few things helpfull...

I cooled it down on 120vto 2 degrees.
I know it worked from before as i had tested it.  I have never used the 12v and the propane

I did no know how long the propane would last, I calculated it would work for ~20 days on a 20 lb tank this is leaving lots of unknowns
.

anyways I cooled the fridge filled with food down to 3 degrees on our way for a 15 day camping trip.
before I left with the truck, I switched it to the 12v  trailer power. When we got there 4 hours later, the fridge was 12 degrees.  I turned it to propane and it cooled off more down to 4  degrees(celsius) then it was up and down for a week between freezing ,0 and 12 degrees so we were a bit worried. then we discovered after reading the instructions for the fridge that if you block the shelves with paper or something large, the flow of air is impeded.  After that we were careful as to how we packed the fridge and it made a big difference.  we were able to keep a decent temperature ~4 degrees with the knob on 9 (the outdoor temps were 35*c daily.)

After selectively packing the fridge we had no problem keeping it cool and was confident in it's operation.
So to make a long story short, pack your fridge with lots of airflow and there should be no problems as long as your system is working.

[AustinBoston]

All this talk about fridges..... after reading about all the bad experiences I was leary about using my fridge.  My 19month  old son is dependant on growth hormone, I needed to bring a supply for 2 weeks. so we decided to use the dometic 2010(?)  not sure right now.   fridge that came with my '94 jayco 1207

anyways I found a few things helpfull...

I cooled it down on 120vto 2 degrees (36