RV Fridge: Do You Need a Battery to Run on Propane?

Know your equipment!

It's a good idea for every RV owner to know the details of your equipment so you won't be get stuck in a bad place while on the road or dry camping.

Today we're going to explore RV fridge use and their requirements.

There are various types out there, and those RV fridges work in different ways. Let's dig in to the different types and you can look at the section that matches your fridge model.

Types of RV fridges

Your RV fridge works differently than your residential fridge. Residential refrigerators use a compressor system to pump the coolant around.

This is why they are sometimes called compressor refrigerators. A compressor fridge compressed a gas refrigerant to a liquid, cools it, then returns it to a gas to get cold air.

You may have heard that RV fridges are propane refrigeration, but the propane itself is the fuel, not the refrigerant.

You're most likely to have a type of RV refrigerator that uses a heated ammonia process to create the cool internal temperature zone. These types of RV fridges are called absorption refrigerators.

I'll spare you the lesson on how you can use hot air to make cold air. It means that we can use a heat source as the primary power to create a cold fridge.

Without any moving parts, RV fridges are very reliable.

How do I know what type of refrigerator I have?

The best way to get all of the information you can is to do an internet search of your brand and model fridge.

Alternatively you could open the cover on the outside of your RV and inspect the area.

A quick inspection of mine shows low voltage electrical lines and a propane line. An AC outlet with a cord is also running to the fridge.

This alone can be deceiving. It turns out that my RV absorption fridge cannot use 12 volt DC power as the only power source.

I need to remove another cover to show that the DC power is merely on a 5 amp fuse. This is not nearly enough 12V power for the heat source.

I can even see there's a spot on the control board to attach the DC heater, with no wires connected.

This is also seen on the front control panel, where I have options of AC power or propane, but no option for battery.

Needs of each type of RV fridges

Propane-powered RV refrigerator

It's very unlikely that you have an RV fridge that only runs on liquid propane gas (also known as lp gas). There is likely another energy source.

Such a system would use a mechanical thermostat and valve. It would require you to manually light a pilot light when first operating it.

There would be no indicator lights or sort of logical controls involved.

If propane is the primary energy source, then it needs an electrical power source to run a small control board with an ignitor. This creates a spark to start the propane flame, after the electric solenoid gas valve opens to allow propane to pass to the burner.

This is almost certainly going to be a 12-volt system. Therefore it will need some power from your RV battery to run.

It won't need much electrical power. This means you can expect it run a long time even if you don't have a fully charged battery.

I tested the power needs on the fridge in our motor home, it used less than ½ an amp of our RV’s battery power.

You cannot manually light the flame on a propane refrigerator for it to run without any electricity.

The system is designed to fail safely. The gas valve that opens to allow propane to flow is spring-loaded to shut off if electricity is removed.

RV propane fridges don't use much propane. We ran our fridge and water heater from a barbecue propane tank for several days. We still had a good amount of propane left when we returned home.

Battery-operated RV fridges - Definitely Needs a Battery!

This kind of system relies solely on battery power for heat and control panel. Most likely it runs on your RV's 12 volt dc battery.

You can expect it to draw a significant amount of power from your house batteries. It will vary with your specific model but I would expect it to pull 20 – 30 amps when running.

This amount of DC power is fine if you're travelling (using the engine to maintain the current) or have a lot of solar panels. It would quickly deplete the batteries in a stock system, meaning a short run time.

AC Powered RV fridges

Though a residential-style refrigerator would use AC power, you're not likely to see compressor-driven refrigerators in the RV world. You can, however, use AC power to heat the ammonia in an absorption RV refrigerator.

Using AC power is simple if you're on shore power or portable generator. It can also come from DC power through an inverter, which essentially makes it a battery-operated fridge.

The fridge in our motorhome pulls about 3 amps of 120V AC power when using this mode.

We try to have our RV fridge run on AC power as much as we can. The less propane we use the better! Propane power is a great option, but finding a gas station that can fill our on-board tank is a hassle.

With this type of fridge you're not likely to have an AC only fridge. If it's capable of running on AC it likely uses 12-volts for the control board and can operated with different energy sources.

2-Way RV Refrigerator Power Needs

Modern RV refrigerators can work with multiple energy sources.

2-way fridges can work on one of two primary power sources. In our case it means the primary energy source can be propane or AC power. The controls, however, run on 12-volt DC power.

I know this means I actually have three energy types going to the fridge. It's not set to use DC power as the heating energy, so that's not counted.

What this means, however, is I need to have 12-volt power to have my fridge run. I could have a full tank of propane and be hooked into shore power, but if my 12-volt system isn't working, the fridge won't work.

Two-way fridges are very common in RVs. They meet the needs of campground life and boondocking. You're ready for any type of camping trip.

3-Way RV Refrigerator Power Needs

If you have a 3-way fridge it means the power source can be AC shore power, propane, or DC battery for the heat source. Once again we can expect the control panel to operate on DC power.

Three-way fridges are the best option to maintain your fridge temperature with any power supply.

RV Fridge Power Needs - Conclusion

People often ask if their RV fridge requires 12-volt battery power to run on propane.
The short answer is yes it does; you need to have battery power to operate your RV refrigerator.

The exception to this is if your propane RV fridge requires a pilot light. If it does, it might operate with no electricity.

If you're looking to purchase an RV fridge, look at the 3-way RV fridges. These are the most flexible to accommodate any situation.