Cool Info on Fridge/Freezers
The convenience of having a portable fridge/freezer is now enjoyed by people from all walks if life. From day-trips and outings to extended trips away you will be able to keep your food & drinks cold or even keep ice cream and meat frozen.
WHAT SIZE FRIDGE?
The most common size that travelers use is around the 40 litre capacity mark. With careful packing, this can hold enough food to feed two adults and two young children for at least two to three days. So the number of people and the duration of your trip will impact on the size of fridge you require. The maximum size of fridge you can take will be limited by the space available in your vehicle, weight limits and the power available (bigger fridges will draw more power or use more LPG).
WHAT TYPE OF FRIDGE/FREEZER?
There are many different types of fridges available, so firstly you will need to think about the climate you'll be travelling in (summer/winter); how much food you'll be taking; how much will be frozen; and will you be staying in one place or moving every day?
There are two main types of fridges and each of these has advantages and disadvantages in different situations...
Compressor 
These fridges use a compressor, just like your home fridge. They run off 12, 24 or 240 volts, meaning that they can be used at home, in the car or in the van.
- Power source: 12v, 24v or 240v (some fridges may need a transformer to run off 240v).
- Can run on LPG? No.
- Can freeze food? Yes.
- What is the maximum amp draw when first started on 12v? Draw will average between 4 to 7 amps per hour depending on size and type of compressor.
- Average amp draw once brought down to temperature on 12v? Will average between 1 to 4 amps per hour depending on size, compressor and the climate condition.
- Noise level? Medium.
- Fast cooling? Yes.
- Capacity range (litres)? Commonly between 18 to 110 litres.
Absorption 
- Power source: 12, 24, 240 volt or LPG.
- Can freeze food? Only the RC1180 and F400 models from Chestcold (but not in high temperatures). Other models on the market will cool but not freeze.
- What is the maximum amp draw when first started on 12v? Draw will average between 7 to 10 amps per hour depending on the size and model.
- Gas usage? On average a 3-way fridge will run for approximately 3 to 4 weeks on a 9kg gas bottle.
- Noise level? Low.
- Heat output? High.
- Fast cooling? No.
Tip:If you are staying in one location for more than a few days and do not have the ability to run your fridge off 240v or recharge your batteries then a 3-way fridge will be more suitable for your needs
Tip:When using a 3-way fridge attach a bullseye spirit level to the top of the fridge so you can be sure it is level when the fridge is running.
POWERING ELECTRIC FRIDGES
The power draw of a fridge is referred to as 'amp draw'. For a compressor fridge, this could be 6 amps when working hard, reducing to 2 amps when the contents have cooled down, then zero when the thermostat cuts out.
Over a 24 hour period this is what we call your average amp draw. This can be very difficult to calculate because the power consumption varies so much when the ambient temperature is not consistent and also how regularly the fridge is being opened.
To calculate the total current consumption for a 24 hour period you multiply amps by hours, so if your fridge uses 2 amps average, then over 24 hours it will use 48 amp hours. Measuring the amp hour usage of a fridge is a good reference and measure, because it is comparable with battery capacity in amp hours. Also you can add amp hour usage for different loads - e.g. if your tent light uses 1 amp and you use it for 4 hours a night i.e. 4 amp hours per day, then your total draw from the battery per day will be 48 + 4 amp hours.
Tip: You should not plan on drawing much more than 50 amps from a 100 amp hour battery before recharging it.
Tip: When packing a fridge use already cold or frozen food to save power.
Tip: Bring the fridge temperature down at home on 240v to save power before you have it running off 12v
Tip: Watts divided by volts = amps.