Other forms: alternators
An alternator is a generator that powers a running vehicle's electrical components and maintains the battery's charge. If your car won't start, you might need to replace the battery — or you may have a broken alternator.
Alternators are devices that convert mechanical energy, usually rotational force from an engine or turbine, into electrical energy. Alternators get their name from the alternating current (A/C) that they create. They are an essential part of any car, keeping the battery charged and powering the headlights, stereo, and heated seats. Large power generators, yachts, and some trains also rely on alternators to keep their electrical systems running.