What is an Alternator?

An alternator is a type of electricity generator fitted inside the engine of a car. An alternater uses the force and motion of the internal combustion engine to produce electricity to recharge the battery, and power the lights and any other electrical/electronic equipment inside the vehicle like fans and radios. Older models of car had an equivalent of an alternator called a “generator.” A “generator” produced direct current (DC current); an alternator – which should also technically be called a generator as it takes one form of energy and uses the principles of electromagnetic induction to produce an electrical current – produces alternating current (AC current), hence the name “alternator.” A typical alternator puts out between 500 and 1000 watts of energy.

In some models of 4×4 vehicle, the alternator can be used to power accessories such as spotlights and winches. This type of alternator would be particularly useful to have on hand during a domestic power failure, as it can generate a good wattage to keep essentials (e.g. the refrigerator) running.

If the alternator breaks down, the battery in the car usually has enough charge remaining to drive to a mechanic for repairs, as long as inessentials such as radios, fans and, if possible, the lights are turned off. You can test for alternator failure at home with a voltmeter, but replacing an alternator should be done by a mechanic, preferably an electrical automotive specialist.
We hope that helps answer the question ‘What is What is an Alternator?’!

Back to Car Glossary