How Does A 12 Volt Camping Fridge Work?

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12 volt camping fridge

If you are an active camper and camp more often than most, you are sure to have considered buying yourself a 12 volt camping fridge or fridge for your caravan at some point in time. There is no questioning how useful a camping fridge can be, especially in the warmer months to keep your essentials nice and cold.

The working of the refrigerator can be easily understood using the working of the aerosol can. Do you remember how cold it feels when you spray from a can of your favorite deodorant? That is because the liquid inside is stored under tremendous pressure. The liquid is a propellant and mostly propane, which has a very low boiling point of 5 degrees centigrade. The propellant inside the can remains in liquid form only because of the extreme pressure inside the can.

When you spray from the aerosol bottle, you do see some liquid and some gas escaping into the environment. The escaping of the gas is due to its contact with the heat outside the can. Now apply the same principle to refrigerators.

All refrigerators essentially work the same way.

Whether it is a 12V or a 24V or a normal home refrigerator, all of the refrigerators work similarly using the aerosol principle. The only difference is that the gases do not completely evaporate in the air but circulate inside the complicated maze of coils that are behind the refrigerator. 

Let us explain how the cooling process works in two dimensions. 

The parts of the refrigerator that you must know:


The function of the compressor is to increase the pressure and the temperature of the refrigerant vapor to such high levels that the refrigerant can condense by rejecting the heat through the condenser.


The main function of the condenser is to condense the gas into a liquid state through cooling. The condenser is what collects all the heat from inside the refrigerator and expels it outside in the air.

Expansion Valve

The valve is only a pin-hole sized constriction. It performs the function of removing pressure from the refrigerant liquid and allowing it to expand. In simpler terminology, it is an important part that is responsible for letting the propellant change from the liquid to the vapor form.

What happens outside the refrigerator?

  1. The refrigerant gas enters the compressor as a low-pressure vapor
  2. The compressor compresses the gas in the process, superheating it
  3. The superheated gas then travels through the condenser, which is a complicated maze of coils behind the refrigerator. 
  4. The condenser cools the superheated gas vapor in the process, also liquefying it.
  5. The liquefied refrigerant is forced through an expansion valve, which is very small in size.
  6. Since the expansion valve is too small in size for the liquid to pass through, most of it is left behind and comes into contact with the heat outside and travels back into the compressor to repeat the cycle. 

Do you really need a fridge when you are camping? 

It can be extended trips over weekends, or it could mean a little longer than anticipated holidays. Whatever it is and for how many ever days, it makes sense to have a refrigerator so that your food does not get spoiled especially when ice is hard to come by, or just melts too fast.

Is a 12V refrigerator the best for camping?

There are a number of options when it comes to choosing a camping fridge, but in my opinion a 12V system is the best choice for camping. From both experience and plenty of research, it is one of those portable models which can run even when connected with your car battery itself. They are also able to be connected to 12v camping solar panels. The prices may seem to be skyrocketing, but don’t let that deter you. 

From drawing very little conventional energy, it is also designed to take the bumps on the road with grace.

How much does a 12v refrigerator cost?

A quality camping fridge does not come cheaply, in fact, expect to pay more than a standard home fridge for a top of the line model. There is of course cost effective options available for those weekend getaways. Expect to pay between $500 – $2500.

Can a fridge be plugged directly into the cigarette charger?

Short answer is Yes – However this is only suitable whilst the car is running and the cars main battery is being charged. If you run a fridge off the main battery when the car is not running, it will most definitely run the battery flat and your car will no longer start.

It’s best to setup a dual battery setup to avoid over usage of your main car battery, or purchase a battery box with second battery.

Final thoughts...

12V fridge is a great addition to your camping trip. Imagine sipping on cold drinks on the white sands or angling with friends after a hard day in the water.   

Andy Sullivan

Andy Sullivan

A lover of all things outdoors, Andy is an experience camper having traveled the east cost of Australia multiple times and countless trips throughout New Zealand.

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