If your battery warning light comes on whilst you're driving, it means that your battery is no longer being charged by the alternator and is running only on its own charge.
Some vehicles may also be equipped with a yellow battery warning light. This is less serious and if the yellow battery warning light comes on, it means the battery has a low charge. This is often due to the vehicle being driven for mainly short trips only. Longer drives allow sufficient time for the alternator to charge the battery.
If the red warning light comes on, it means the battery is no longer being charged due to a fault with the battery charging system. Some vehicles may also be equipped with a yellow battery warning light. This is less serious and if the yellow battery warning light comes on, it means the battery has a low charge.
The car battery warning light illuminates on the dashboard when the ECU detects a problem with the battery unit or its charging system. It may indicate a low voltage, resulting from a damaged, corroded or worn battery, or a damaged alternator, for example. Keep reading for more information on what different battery indicator lights mean.
The battery warning light looks just like a car battery, with plus and minus symbols within a rectangle. It can indicate a number of things, all relating to the car's battery and charging system.
What does a faulty battery light mean?
If you're not sure which issue is causing the light to illuminate, you can test the health of your battery yourself. Signs of a faulty battery include dim headlights, or if your engine is reluctant to start. The temperature warning light, styled after a thermometer in water, signifies that the engine is overheating.
Common reasons why the battery warning light is illuminated: A flat or failing battery – if the battery can't hold its charge properly, it may trigger the warning light. Loose or corroded battery terminals – this can interrupt the flow of electricity.