Marginal generators do not have enough cajones to START a roof air. For five seconds or so the power needed to start the AC can not be met by the generator alone. But once they get running, the AC draws far less power, and this means the generator MAY have enough power to support the Air Conditioner plus hotel loads.
But couple them TOGETHER for that five or so seconds and the Magnum inverter will supply enough vitamin supplement to generator power to start the roof AC. The trick is: Does your genset have the guts to run the AC and hotel loads (hotel loads are AC power to loads in your rig) WITHOUT RELYING ON THE INVERTER TO KEEP SUPPLYING POWER. Even a battery bank the size of the Chase Manhattan Bank is going to run down sooner or later if the inverter has to keep supplying power to keep the roof air going.
The start boost is ONLY to start the roof A/C then the game ends. The inverter reverts back to battery charger mode and generator power supplies the whole shebang.
Get a ferroresonant line voltage correction device or "Hughes Autoformer" if campground voltage is low. In a campground the inverter won't do a damned thing for you if voltage is low. If you connect to 100 volt shore power don't expect the inverter to have ANYWHERE NEAR the battery charge amperage potential as listed on the package.
