Originally Posted by djchapple

This would also impose a huge drain on the batteries and the motorhome wiring loom.

For example 720 Watt is 60 amps - no standard motorhome wiring can get anywhere near 60 amps. Most circuits have a maximum of 25 amps or much less.

You need a very serious 12V power supply and non-240V charging system to provide such power.

For standard MHs microwaves are a no-no without 240V ehu.