This Early motor vehicles until about the 1960s tended to use DC generators with electromechanical regulators. These have now been replaced by alternators with built-in rectifier circuits, which are less costly and lighter for equivalent output. Moreover, the power output of a DC generator is proportional to rotational speed, whereas the power output of an alternator is independent of rotational speed. As a result, the charging output of an alternator at engine idle speed can be much greater than that of a DC generator. Automotive alternators power the electrical systems on the vehicle and recharge the battery after starting. Rated output will typically be in the range 50-100 A at 12 V, depending on the designed electrical load within the vehicle. Some cars now have electrically powered steering assistance and air conditioning, which places a high load on the electrical system. Large commercial vehicles are more likely to use 24 V to give sufficient power at the starter motor to turn over a large diesel engine. Vehicle alternators do not use permanent magnets and are typically only 50-60% efficient over a wide speed range. -506 Start using energy-saving settings on refrigerators, dishwashers, washing machines, and clothes dryers. "mike brady magnetic motor " and "alternative energy home projects " (include "home energy assistance program new york", "how wind turbines produce electricity ", "geothermal energy home use ", "home energy monitor google ", "magnetic motor hoax ", "Bike electricity generator ", Iowa officials called on Congress and the next U.S. president to create 2 million new jobs in two years through a $100 billion investment in renewable fuels & How many people use wind energy )