This is just an issue of assumption conservation. You can run one heavy consumer of electricity at a time. The microwave with everything else off. A space heater with everything else turned off. I have done this for years at my brother's house. I use a 10 gauge extension cord and run the converter to keep the batteries charged and run a space heater constantly with it set to a 750 watt setting. I watch TV, make coffee in the morning, and keep the batteries charged without issue. I heat water on propane and keep the refrigerator on gas. Never a problem.