A 3 way fridge is a refrigerator than can be powered by any of three different energy sources. These sources of power are usually LPG gas, 240V mains power and also 12V battery power.
These fridges are generally optimized to run most efficiently when using LPG gas. Usually it will be configured to run on propane, but some fridges use butane instead. The option of powering by gas is essential if you will be using your mini camping fridge on extended trips in locations where mains power is not available.
240V AC mains power – such as is used to power your home fridge freezer – is great when it’s available; the supply being nearly limitless. When a camping fridge is intended for use at a powered campground, or perhaps an RV park, you will need this option.
Finally, there may be times when you need to use your fridge while on the road, or making short stops. You do NOT want to power your fridge with propane while you are driving, this would be a very bad idea! Instead, you let your fridge draw power from the 12V direct current car battery. As long as your engine is running – which it will be when you are driving – you will not run the battery down.
You can also utilize the 12V power source on camping trips. However, care must be taken. Do not set your fridge up to draw from your car battery for extended periods. If the engine is not running, you will soon have a flat battery. However, you do have the option of installing dual battery setup in your off-road vehicle. When done correctly you can power your fridge from a secondary car battery, and still have your main starter battery available and unimpaired for starting your vehicles engine.
The versatility of these various power options makes a 3 way camping fridge a popular option for outdoor enthusiasts who want the most fridges for their money.