Distribution Panel On Lunar Premiere

Hi folks,

Quick question,once hooked up to the sites main electrics,what do I set my distribution panel to? There is 3 switches,car,off and caravan. Obviously I don't put switch on to car,but I am confused as to either the off position or to caravan. I don't know if this helps but my leisure battery is a rechargeable one once hooked up to car. Your help would be much appreciated. 

Thanks

Lee