Quattro-IIOverview Sizing Did you Know? The Quattro II is an extremely powerful sine inverter, battery charger and transfer switch inside one compact casing. Like the Quattro, Quattro II has two AC inputs and automatically connects to the active source. Whats the difference between the Quattro II and the Quattro? It has a smaller footprint and even lower self consumption (15W in Zero Load) than the Quattro (35W in Zero Load). In mobile power system applications