alternator

American  

[awl-ter-ney-ter, al-] / ˈɔl tərˌneɪ tər, ˈæl- /

noun

Electricity.

1. a generator of alternating current.

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alternator British  

/ ˈɔːltəˌneɪtə /

noun

1. an electrical machine that generates an alternating current

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Etymology

Origin of alternator

First recorded in 1890–95; alternate + -or ²

Explanation

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.

Example Sentences

You don’t replace the whole robot any more than you replace your car when the alternator dies.

From MarketWatch • Nov. 14, 2025

My van was fitted with a 180W solar panel that fed power to a 95Ah battery that also received charge from the VW’s alternator when driving.

From The Verge • Jul. 15, 2022

According to Firestone, if it stays on, comes on while driving or the car won’t start, it could mean something is wrong with your battery, alternator or vehicle wiring system.

From Seattle Times • Mar. 28, 2022

There was some back and forth about the sickly alternator, and then Peter Derry, 28, offered a solution.

From Washington Post • Dec. 29, 2018

If it were the alternator, the battery would be dead and the lights wouldn’t come on.

From "The Serpent King" by Jeff Zentner