Electrical
What is an Alternator?
The on-board power station that keeps your battery topped up.
Simplified animation — not to scale.
In plain English
The alternator is a small generator bolted to your engine. Once the car is running, it produces the electricity that powers everything — headlights, radio, wipers — and recharges the battery as you drive.
A simple analogy
"Think of the battery as a phone and the alternator as the charger that's plugged in while you drive."
How it works
A belt from the engine spins the alternator's rotor inside a magnetic field, creating an alternating current. That current is converted to DC and sent to the battery and the car's electronics.
Signs of trouble
- ⚠Battery warning light on the dashboard
- ⚠Dim or flickering headlights
- ⚠Car starts fine but dies shortly after
- ⚠Whining or grinding noise from the engine bay
Rough UK cost
£250 – £600 fitted at a UK garage
Always get a written quote. Prices vary by car, region, and parts brand.
Heads up: Carautonomy is for general guidance only. If your car is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.