With the AC300 and B300, you have to feed the beast!! With the inverter on (and no draw), the AC300 draws 30W. It also will not charge if less than 100W is being input. But we ran the chest fridge (constantly), microwave (occasionally) and AC (at night), as well as charging a couple small solar generator. Beginner’s Guide: Cheapest Way to Power Your Van Life!We only took 300W of solar this trip. We plan to add up to four 245W panels, depending on the weight. ("four" may be unrealistic)