Originally Posted by Jarlaxle
My entire conversion--My plans are for no 120V except the shore power connection. EVERYTHING will be 12V, includintg the A/C.
Then you don't want an portable or RV generator! Their reason for being is to produce AC power. You need nothing more than a good battery bank, maybe solar panels and/or a wind generator and a healthy alternator (or two) on your main engine.
I've never heard of a 12-volt Air Conditioner; do you have some information links on such a beast?
Our bus won't have much in the way of AC (120-volt) power but some things just seem to work better that way; like the roof-mounted air conditioners (since I'm not familiar with a 12-volt version). The refrigerator and water heater will run on AC when we're connected to shore power. The refrigerator will run efficiently on DC too but not the water heater; it needs 120-v or propane. I also don't believe there's a 12-volt microwave available; the micro is convenient enough to warrant a place in our conversion.
Really our 120-volt system is minimal; it powers the refrigerator, the water heater, the A/C units, and the microwave. It also powers a couple of outlets for use with our espresso machine, blender, waffle maker, Kitchenaid mixer, etc; these items probably being things that are not necessary for a camping conversion but our bus will be a full-time liveaboard. By and large 12-volt appliances are cheaply made, ineffcient and expensive when compared to their 120-volt counterparts which can easily run on an inverter, shorepower or a generator. Remember watts is watts which in turn is voltage times amperage; a 1000 watt load on 120-volt needs wiring sized for about 8 amps (typical 14/3 house-sized wiring) but the same 1000-watt load on 12-volts is going to use 83 amps...that's some really hefty wire!
On our conversion the Honda EU2000i generators are primarily aboard to provide power for the A/C units, the espresso machine, and the microwave when away from shorepower (the micro and espresso machine will run on the inverter but it's quite a load on the batteries). When not connected to shorepower the refrigerator runs on 12-volt, the water heater on propane and the rest of the above list of appliances relies on power from the inverter when the generator isn't running. All the lighting is high-efficiency CCF (Cold Cathode Fluoresent) 12-volt or halogen task lighting; the water pump and heater fans also run on 12-volt power.