Originally Posted by markopolo
Every van with an inverter has an engine generator. The primary difference between them would be the power output. An 2004 RT 190P could produce 600 watts 110V AC with the van engine running as delivered from the factory.
A basic budget engine generator with 1,000 watts up to maybe 1,400 watts is easy to implement. It gets more expensive if you require more power. That's when you need to replace the alternator with a higher output model or add second dedicated alternator.
If your need is to power a small microwave oven occasionally via running the engine then that is easy and wouldn't cost much to do. If your power needs are greater such as 15 or 20 amps at 110v AC then it gets more expensive and more complicated.
I agree, and with the newer models, which appear to be coming with bigger alternators, the situation of getting basic generator capability is even easier. The Chevy in Marko's example would probably have a 145 amp alternator, most new stuff is closer to 200 amps.
Several folks have been able to run a small microwave on 1000 watt or even 750 watt inverters, like the the very common Tripplite, but it can be very microwave model dependent. Unfortunately, the Dometic micro that so many builders use seems to be one of the more sensitive ones and won't run on many inverters. It seems to need about 1500 watts of inverter to operate.
One thing to remember is that on a very basic system, you may, or may not, be removing charge from the battery when using high load stuff with the van running. It can go either way, based on the vehicle and load, so you need to be aware of that, and figure it into you daily usage monitoring.