Reply #15: It;s actually in use with a generator.

[lapfog_1]

But you could hook it up to car battery terminals with the car running.

Many over the road truck drivers have such inverters permanently wired into their electrical system with deep cycle marine batteries providing for their sleepers electrical needs when the engine isn't running. There are even "APUs" that you can buy that are much like reefer units for trailers. That is, a genset totally unconnected to the engine wiring that starts automatically when the batteries are getting low and provides watts to a major inverter for running everything in the sleeper. I believe that many of the larger RVs have similar setups.