What to Do If Your Battery Light Comes On

While some warning lights on your dash don’t indicate an immediate issue, your battery warning light is one that you do not want to ignore.

A battery warning light means that, for some reason, your battery is not recharging and it’s only a matter of time before driving your vehicle drains whatever charge is does have.

When that happens, your vehicle will essentially “die” and even a boost from another vehicle will only provide you a small amount of power in the battery. It’s best to determine as quickly as possible whether you can troubleshoot the issue or if you need a professional to take a look.

How does the battery work?

Under the hood of your vehicle there is a 12-volt rechargeable battery. This battery feeds an electrical current to the starter in order to get your engine started. Once the vehicle is started, the alternator supplies power to your vehicle’s electrical system.

The alternator, located next to your engine, also recharges the battery as your engine is running, ensuring that once your vehicle is turned off there is enough power in the battery to start it again. The serpentine (or drive) belt, named for its long and winding appearance, drives the alternator via the engine. It maintains effective and smooth operation of your alternator, power steering pump, air conditioning and – in some vehicles – your water pump.

Your vehicle’s electrical system also includes fuses, which are necessary in preventing over-voltage and short circuiting. They are designed to “blow” when the current flow of a circuit reaches unsafe levels. Once blown, electrical power is prevented from reaching devices on that circuit.

What does the battery light mean?

The main purpose of your vehicle’s battery light is to warn you if the recharging system has failed in some way, meaning that your battery is no longer charging and is simply running on whatever charge it has left. The light works on a circuit that measures the voltage produced by the alternator – the light turns on if the amount of voltage produced is low.

Basically, the light indicates a battery charging problem. If the light comes on and stays on while driving, this means that your alternator is running solely on energy stored in the battery. If you continue driving, your battery will eventually drain and your vehicle will stop working.

What to do if your battery light comes on:

If your battery light comes on, you should immediately turn off everything electrical in your vehicle except for the headlights in order to conserve whatever charge is left in the battery. This includes the air conditioning, heating, stereo, interior lights, heated seats/mirrors, phone chargers and blue tooth accessories.

Watch for overheating and loss of power steering. If either of these events occur, turn your vehicle off immediately.

There are steps you can take to troubleshoot the issue to determine why the battery light has come on:

1. Inspect the battery.
Check your vehicle’s battery for signs of corrosion on or damage to the terminals. Remove any corrosion and make sure the clamps are secure on the terminals.

2. Check the alternator.
Take a look at your alternator for any loose or missing electrical connections.

3. Look at the serpentine belt.
If you are having issues with overheating and loss of power steering, it’s likely caused by the serpentine belt. Look for major cracks or breakages in the belt – or complete loss of the belt.

4. Check your fuses.
Although fuses do not cause direct issues with battery charging issues, it’s worth looking to see if any fuses are blown and replace them.

5. Test the battery.
Once you have worked through these steps, test your battery by starting your engine. If the light turns off, you have likely fixed the issue. If the light remains on, you probably have an alternator issue.

Have questions about your battery or any warning light? Feel free to contact us!