Running a fridge on 12v or 240v

Depends how long you want to camp away from power.

If I was you I would connect both the 12 volt and 240 volt unless you have plenty of solar and at least 2 x 105 amp hour batteries.

One thing i was just pondering is with a 12v ,240v fridge does it have an inverter built in changing 12v to 240v or a transformer changing 240v down to 12v?Thanks all

It's always better to charge an unloaded battery, especially to get the best out of a smart charger. That way, when the charger is trying to sense the battery voltage, it is not influenced by battery voltages being altered by applied loads.

So I would get the 240V wiring done.

Cheers

I think most of these new units have a 12/240 detect system whereby whilst travelling or parked it will operate on 12v., then when you connect to external 240v. power it automatically changes from 12v. to 240v.
If this is in the case of yours it should have a 240v. lead you simply plug into the 240v. outlet placed for a fridge connect and a dedicated high current 12v. supply to the appropriate terminals.
mike

My two cents worth.
I would go for wiring both as, say you arrive at a 240 source of power (eg Caravan park)
or you run a generator, you will charge your batteries much faster if the fridge load is not
on your batteries at that time

Your mate does not seem to know how most 240 V chargers (and for that matter solar controllers) work. As multi stage chargers go through their cycle they detect that the battery is fully charged by the reduction of current whilst they are in the absorption stage. When they are in the absorption stage they are producing a constant voltage. During this time the charge current drops down to 10 to 20% of their rated maximum current output. When the charger detects that the current has dropped that low they switch to float or maintenance charge.

However when you put a load on the battery the charger will attempt to supply that current. The internal circuitry of the charger detects that the current is greater than the current where it switches to float charge. It then switches back to the absorption stage. This in turn raises the system voltage to a value that is not conducive to long battery life. If you have the fridge wired only to the battery then the battery will be receiving a charge voltage instead of a float voltage when your fridge is working. If you connect the fridge to the mains power when it is available then your battery will not be subject to this continual overcharge when the fridg motor is operating.

+ 1 for the 240V, but for a different reason.

If your fridge uses up to say 5A and an average of 1A then you can subtract that from the charger capacity. It you have a 25A charger then not much of an issue. But if you have a 10 charger then you lose charging capacity. The charger will suffer, the power station won't.

I don't believe having the fridge connected to the battery while charging. They cycle on and off and the off time is more than enough for any charger to see that the battery is charged. Though if you have a small capacity charger you lose every way.

HI
As usual , You will get more relevent ANSWERS ,if you post the fridge brand & model Number
Like oils ,all fridges are not the same!!
Most 3way ridges have a higher rated element on 240V
So THEY WILL COOL BETTER & FASTER on 240V

Large 3way fridges can have a high wattage 12V element ,some even 275W that means 23A being taken from you battery /charger just for the fridge

PeterD has made THAT point & the possible consequences

3way fridges are not intended to be used from the van battery
THey SHOULD be connected to the vehicle with their own independent heavy cables
[Size will depend on run length & fridge 12V wattage]
They also require some form of isolation from the car battery when the engine is not running.,
Some models have THAT function built in ,so again MODEL number & BRAND is important!

PeterQ