To get 7amp from my onboard charger/power supply(thats what its rated at)how many watts/amps must i put in, either mains or genny. my current genny is a 650w cont, 800w peak and it dont seem to be up to it. also can i use the gennies 8amp dc battery charge facility AND still connect the genny to the 240v mains socket without having to turn off the onboard charger. thinking of getting a 2.2kw pure sinewave kipor so i can run the aircon when off hookup. john.