What Makes an Rv Fridge 12V

It has a 12V heating element in addition to the 120V heating element.

The 12V system is marginal for a smaller fridge but probably wouldn't work well at all with a bigger unit.

3 way fridge had a DC heating element.

At best they were for maintaining fridge temps while in transit....using the DC function while parked would result in 2 things
1) Low battery voltage due to heater element draw
2) Warmer fridge temps due to lack of dc heater element heating ability (215W max...typical element 175W)

Que tal Chris. Your previous fridges may have been smaller as well. 3 way fridges are still available but only in smaller sizes. They are usually found in truck campers and very small trailers. An absorption fridge uses one of three sources for heat if it is a three way. A 12 volt element, (uses a lot of power) an AC element (usually around 4 amps at 120 volts or 40 amps at 12 volts through an inverter) or a small propane flame. A two way fridge simply drops the DC electric element.

You can get a larger 12 volt fridge but it will be a compressor type fridge, quite often with a Dan Foss compressor. Dometic makes them and they usually use around 4 to 5 amps DC at 12 volts when cycled on. Much less power than the RV absorption fridges. Equivalent to about 4 or 5 light bulbs. I would recommend a robust solar system (400 to 500 watts) and at least two 6 volt batteries if going this route. We will be doing this in our little rig when the dometic dies. It is on its last legs but hanging in there.

Hasta la proxima amigo.

Even the older 3-ways on 12-volts did nothing more than slow down the inevitable rise in temperature - hopefully giving enough time to limp from power pole to power pole or light off the LPG at the destination.

To equal the performance of the 120 volt element in a typical 6 cu ft fridge, a 12 volt element would need to pull about 27 amps. Nobody would run that very long off the battery. The DC wiring from a tow vehicle to a trailer can't carry that much current, so the only practical application would be in a motorhome while the engine is running. Probably too limited a market segment to make it worth it for the fridge builder, and the beefy wiring to support it would run up the cost of the motorhome.

As was stated, they were power hogs that were poor performers at best.

In the absence of 120 volt power, propane is a FAR better option.

There was a thread on the Class C section recently and one poster kept asserting that 2 way fridges were the 'cheapo' versions and out-of-date because all the 'good' units had a 12 volt option. It takes all kinds. LOL.

When I had a trailer I tried running the fridge using an inverter. After about 4 hours the battery dropped too low and the inverter shut off. The wiring from the TV to the trailer was too small to keep the inverter running. I never did try to improve the wiring.

The compact fridges have the same wattage 120v and 12v heating element.
this one is speced 115 watts for both 120 and 12v, uses no 12v on propane.
https://www.dometic.com/d5cc849a-fb08-49a0-a703-d488f773cf9e.fodoc

John & Angela wrote:
Que tal Chris. Your previous fridges may have been smaller as well. 3 way fridges are still available but only in smaller sizes. They are usually found in truck campers and very small trailers. An absorption fridge uses one of three sources for heat if it is a three way. A 12 volt element, (uses a lot of power) an AC element (usually around 4 amps at 120 volts or 40 amps at 12 volts through an inverter) or a small propane flame. A two way fridge simply drops the DC electric element.

You can get a larger 12 volt fridge but it will be a compressor type fridge, quite often with a Dan Foss compressor. Dometic makes them and they usually use around 4 to 5 amps DC at 12 volts when cycled on. Much less power than the RV absorption fridges. Equivalent to about 4 or 5 light bulbs. I would recommend a robust solar system (400 to 500 watts) and at least two 6 volt batteries if going this route. We will be doing this in our little rig when the dometic dies. It is on its last legs but hanging in there.

Hasta la proxima amigo.

Thanks John. We have a 400W panel and two 6V batteries. I want to add two more to the group. I just always liked the idea of the 12V fridge taking advantage of the solar when going down the road or during the day when the sun is good. We'll be in touch. Saludos!