Will fridge run without battery power?

[crazylev]

Hello.

Our couple of year old Dometic fridge is working fine both on gas and AC.

If you are running the fridge on gas, and let's say your batteries run down, will the fridge continue to cool and operate more or less as normal? I know that propane will still be going to the unit, but will it just shut down, ruining food if there is a batt. meltdown?

The only thing that I can see that may not work is the "convection" fan, but that wouldn't be missed

Anyone?

Jonathan

[lewster]

Hi Jonathan,

All modern RV refrigerators have a control board that acts like the 'brain' of the unit and REQUIRES 12VDC for the unit to operate. One of the things that it controls is the gas valve. If no voltage is present, the valve will close and no LP will flow to the burner resulting in no heat for the refrigerant and no cooling for the refer.

[bhayden]

The manual will tell you what voltage the unit will shut down at. I think on mine it "shuts down" at around 9 volts and the "Check" light comes on. Then around 5 volts the lights shut off. Mechanically the Dometic seems to work pretty well but the control "logic" is terrible. LEDs cost only pennies and draw virtually no current. It wouldn't have been hard to have a simple display for voltage (green / yellow /red) and a pizzo alarm when it shuts down would be really nice. Thermostatic control or at least some sort of crude indication of temperature would be nice and the "Climate Control" continuing to drain the battery (at ~1/2 Amp) when the fridge is turned "off" is just inexcusable. A lithium cell like digital cameras use would have operated the control logic with the gas valve in "Manual" mode at least overnight and probably longer. For the money they charge these "deluxe" features don't seem like too much to ask, do they? If they really wanted to go "all out" a solid state charging circuit could be built using the temperature differential from the flame to run the unit for as long as there's gas. But they didn't even include a cheap AC to DC converter so that the fridge can run on AC without the trailer battery. Stupid!

-Bernie

[crazylev]

Bernie and lewster.

I does seem odd that even though gas is getting to the burner (assuming the pilot is already lit) why the unit should go off in the event of a battery failure. It should just be running on gas. Period. Or am I missing something?

Now I suppose I should schlepp along a Coleman cooler for those just in case times...

Jonathan

[2airishuman]

Originally Posted by crazylev

assuming the pilot is already lit..Or am I missing something?Jonathan

hi 'lev

well they don't have traditional pilot lights anymore....

and the SAFETY feature is no juice no gas....since the controls are all electric.

i can report (but i don't recommend this) that my fridge has continued to cool with 12v levels below 9.....
i experienced this by accident...and it is possible the metering was in error.


cheers
2air'

[47WeeWind]

Originally Posted by crazylev

... If you are running the fridge on gas, and let's say your batteries run down, will the fridge continue to cool and operate more or less as normal? I know that propane will still be going to the unit, but will it just shut down, ruining food if there is a batt. meltdown? ... Jonathan

Hi Jonathan:

Not all modern refrigerators require battery power to operate on propane; only those with complex operating systems for "convenience" or perhaps for "safety" do. One old fashioned exception is a small Norcold fridge seen here:

http://www.norcold.com/n300.cfm

which has simple, non-battery operated manual controls - how 'bout that, a "step forward" happily not taken !!

I'm sure it won't be too long before Dometic begins selling propane powered battery chargers so you can charge your battery to be able to operate your computer-controlled propane fridge.

[47WeeWind]

Originally Posted by crazylev

....Now I suppose I should schlepp along a Coleman cooler for those just in case times... Jonathan

Jonathan:

I've heard a nasty rumor that Dometic is just about ready to announce their latest RV convenience and safety invention: a circuit-board controlled 20 pound block of ice for Coleman and other brand coolers. Every ice block will have electronic sensors spread throughout it that will feed back temperature and moisture level data to the control board, that will then adjust the melt-down rate for safe, linear temperature-controlled ice cooler cooling. If it senses the ice and/or ambient water temperature is too cold for comfortable human contact, it will shut down the melting process and sacrifice the food in favor of avoiding any unpleasant cold temperature direct skin sensory experience that may adversely affect the pre-programmed camping experience (available separately - see your dealer).

An optional, extra cost module can be added at the factory to the circuit board; it sends electronic brain waves to your brain, which waves tell you what to think of this great new experiece, minimizing the sense of sorrow resulting from food loss while simutaneously increasing the sense of camping safety and favorable product reaction.

[crazylev]

Fred.

I'm placing my order today!!!

JL

Thanks fo the info.

[rseagle]

Don't forget, that at least on new Airstreams (mine's a 2004 22' CCD), if the battery voltage drops below 10.5 volts, the solenoid switch to the battery will close and won't allow a recharge from the trailer's DC charger. You will need to get the voltage up above 10.5v by either your vehicle's alternator, a generator's DC charging or an external AC to DC charger connected to the battery. I found out the hard way! And it's not mentioned in the manual.

[Chuck]

the whole "fridge needing 12v" thing is just rediculous. Didn't anyone tell them that this makes the whole thing self-defeating????

My family used to vacation at a rustic cottage where there was 0 electricity. no a/c, no d/c, no solar...not even static. Old servel gas fridge kept everything nice 'n cold, though, no problem-o. gas lamps kept the place lit at night, and the gas water heater supplied ample hot water. (a nearby brook and gravity provided running water). The appliances in the RV should work just the same. The "option" to work on a/c or d/c electric is nice; neither should be "required".
I wonder if you can even get replacements for these old "house model" gas refrigerators?

[Flathead1984]

Originally Posted by crazylev

Hello.

Our couple of year old Dometic fridge is working fine both on gas and AC.

If you are running the fridge on gas, and let's say your batteries run down, will the fridge continue to cool and operate more or less as normal? I know that propane will still be going to the unit, but will it just shut down, ruining food if there is a batt. meltdown?

The only thing that I can see that may not work is the "convection" fan, but that wouldn't be missed

Anyone?

Jonathan

I am new to all this. I have had my FC 2020 25 in storage for 3 weeks with everything tuned off and electric set on store. I wanted to start the REFER on LP to run and cool down. I turned on the gas. In side, I have no reading on the Dometic refer. How do I start it and run on LP for a few days? Cannot find a think in the manual.

[Bill M.]

The fridge will not run on propane if the batteries are too low. It uses battery power for the control board and for ignition. The batteries have to be pretty low. The fridge does not draw much power on propane but it does need the voltage.

I do not think there is inherently any thing wrong with the new electric only refrigerators. With either you just have to understand you system requirements and make arrangements to provide those requirements for the conditions you are camping under. For me, since I also have to keep a CPAP operating, I carry a generator even though I have a propane refrigerator.

One can carry a extra battery in a little box and plug it into a 12 volt socket in the trailer for emergencies. Or carry a generator. Or one of the Lithium power supplies. Or manage the batteries. Or spend a fortune on a solar addition. Or go to Jackson Hole NAPA and buy a new set of batteries when you really screw up. Or ride around in the truck all day because the trailer is 37 degrees inside and you do not have enough power to run the furnace. Or let the batteries run down and buy ice for the cooler everyday. I have done it all except for the solar. The result of my experience is that I now put the generator in the truck at the start of camping season and do not take it out again until the camper is winterized for the next season.

[n2916s]

You also need 12VDC to open the gas valve at the base of the reefer. No DC no propane...

[TG Twinkie]

I agree with Chuck.
They still make water heaters that don't require a 12 volt power source.
The original refer in my '74 Argosy 26' still works. No battery required.
KISS

[Bill M.]

Flathead: Do you even have a LP fridge or is it the new all electric? On the LP models there should be a control panel on front with little lights on that tell you if you are on gas or LP and what temp setting it is on. I thought I read that all the new ones are electric only?

[stevejones]

Originally Posted by Flathead1984

I am new to all this. I have had my FC 2020 25 in storage for 3 weeks with everything tuned off and electric set on store. I wanted to start the REFER on LP to run and cool down. I turned on the gas. In side, I have no reading on the Dometic refer. How do I start it and run on LP for a few days? Cannot find a think in the manual.

Your battery switch needs to be set to USE not STORE. If in STORE the refer is not getting the 12Vs it needs to run.

Steve

[Steamguy]

I've had this actually happen. Trailer batteries died while out camping, fridge quit. Hooked up the tow vehicle, started the engine, supplied enough power to run the fridge for an hour or so to cool it back down.

Lots of answers above, let's see if I can get them into one post.

The gas valve is held OPEN by a 12V solenoid. That way, if power goes off, so does the gas. The control board for this function can be as simple (then: one temp - usually "mostly cold enough") or as complicated as necessary (now: a number of settings, most useless) to try to maintain the box at temperature.

So you HAVE to have battery power for the fridge to work.

As above, Servel is the one brand that still runs just fine without external power. They're known for being in every Amish household, and are available through Lehman's Non-Electric Catalog.

Hope that helps.