Inverters must be dimensioned in two ways. The first is by considering the electrical power Watts that the inverter can supply during its normal and continuous operation. Inverters are less efficient when they are used at a lower percentage of their capacity. For this reason, it is not convenient to over-dimension them, they must be chosen with a power as close as possible to the consumption charge. The second way to dimension the inverter is by jeans of the starting power. Some inverters can supply more than their nominal capacity over short periods of time. This capacity is important when motors or other loads are used that require from 2 to 7 times more power to start than to remain on once they have started (induction motors, high power lamps).