HOW MUCH POWER WILL MY FRIDGE USE?
A mid-sized 12V fridge (90-100) will use around 25-35 Amp hours per day and a large 12V fridge (150-220L) can use 50 - 70 Amp hours per day.
Typically a fridge should cycle so it runs for a period of time and then is off for the same period of time. In this way the 12V fridge will run for 10-12 hours per day. If your fridge cycles on and off quickly its likely to be a voltage issue, low battery voltage or a cable that's too small and resulting in voltage drop between the battery and the fridge.
GAS FRIDGES CAN USE POWER TOO!
Gas fridges with Electronic Power Selection will use around 0.2Amps per hour, 24 hours per day, that's 5Amp hours per day in total.
IS IT WORTH CHANGING FROM A 12V to GAS FRIDGE?
Unless there are unusual circumstances, we typically recommend that customers stay with their existing fridge for the following reasons:
- It can cost the same again as the gas fridge will cost, simply to install the new fridge properly. That $1200 Gas fridge could cost another $1000 to install.
- Many motor homes aren't set up to allow a gas fridge to be properly vented (there are too many windows or windows are in the way). Venting of gas fridges must be done properly or the performance of the fridge will suffer and the fridge may be damaged if it gets too hot
- 12V fridges have a number of benefits
- they dont need to be switched off for driving
- they can't be blown out in the wind
- they don't go out when the motorhome's not on a level surface
- once solar's added there are no ongoing running costs for the fridge
- the LPG doesnt need to be run continuously so there are fewer safety concerns
- adding solar charging to the motorhome is now far cheaper than replacing the fridge. Whereas it could cost $2000 to change from a 12V to a gas fridge it may only cost half that (or less) to add enough solar to run a 12V fridge, and there are no ongoing consumable costs (LPG).
HOW MUCH SOLAR MAY YOU NEED TO RUN A 12V FRIDGE?
A single 150W solar panel should provide enough solar power to run a mid sized 12V fridge 9 months of the year. Only in winter will the solar input be less than the fridge will use.
Typically we would recommend that a motorhome with a 12V fridge should start with a minimum of 1x140W solar panel and if they want to achieve extended freedom camping they should have at least 300W of solar panels.