Dim or flickering headlights
Battery warning light on the dashboard
Slow or weak power windows, radio, or other electronics
Dead battery or frequent jump-starts
Engine stalling or rough running
Difficulty starting the car
Whining, grinding, or squealing noises from the engine area
Burning smell from the engine bay
Battery that keeps losing charge
Electrical accessories acting inconsistently
Voltmeter reading below normal
Corroded or loose alternator wiring or connections