alternator
/ˈɔltərneɪtər/
noun
- A device in a vehicle that produces electricity to charge the battery and power the electrical systems while the engine is running.
- When the alternator failed, the car's battery quickly drained and the engine stopped.
- The mechanic tested the alternator and found it was not charging the battery properly.
- A modern alternator is more efficient than older generators at producing electricity for a car.