What Does the Battery Light Mean?

It’s a pretty common horror scenario: you are driving along, minding your own business, when suddenly the battery light goes on in your car. It can be challenging to know whether it is safe to drive with the battery light on or not. If you are not experienced with cars making that call may be stressful.

Why is the battery light on in my car?

First things first: if the battery light comes on in your car when you turn it on, you probably have nothing to worry about. Sometimes the battery light will come on when you start your car, but then the light will quickly flick off. If this is the case, pay it no mind.

In the event that the battery light comes on and does not go off, this is indicative of a deeper problem. To even begin to understand what might be wrong, it’s important to understand how your car’s electrical system works. Your car battery produces 12.6 volts, and this is used to start the vehicle and also to power your car’s multiple electrical systems. The majority of cars are also equipped with something called an alternator, and the alternator recharges the battery. Without an alternator, the battery in your car goes dead very quickly.

Usually if the battery light goes on in your car, there’s either a problem with the battery or the alternator. Sometimes there may also be a deeper problem with your car’s wiring.

Can You Drive Your Car With the Battery Light On?

The short answer to this is, “Yes.” The full answer is, “Probably not for too long.” The car’s battery light coming on generally means that there is something preventing your car’s electric system from charging off the battery. Basically, if you see the battery light going on in your car, you shouldn’t expect to be able to drive it for very long.

The exact amount of time that your car will be able to function with the battery light on depends on many factors, but assuming that the alternator is the issue (this is the most common issue) it is likely that your car will lose battery power after 30 minutes. This is about how long it takes most car batteries to completely discharge. Of course, this depends on your battery and your car, and some cars may be able to last longer while others may die quicker.

If the issue is not with the alternator but with something else in your car’s electrical system, like faulty wiring, you may have even less time.

Basically, if you see the battery light in your car click on and it’s not just flickering for a bit when you twist the key in the ignition, your head should be on a swivel for the nearest mechanic or AutoZone. However, rest assured that if the battery light on your car goes on, continuing to drive the car will not damage it. The worst thing that will happen is the battery will die and the car will stop functioning until it is replaced or recharged.

Other signs of problems with your car’s electrical system may be windows that will not roll up or down if your car has power windows, or a radio that will not turn on. You may also experience problems with the headlights or climate control.

Why is the Battery Light On?

Modern cars are very dependent on their electrical systems. In addition to running the basic systems of the car, they are used to operate the complex computer systems that most cars come with these days. Due to this high dependence on electricity, your car is programmed to pay great attention to the voltage running through the car. Should the voltage start to go below a certain threshold, your car is going to alert you that there is not enough electricity to run the car’s systems. If your battery light is on, this means that the car is operating only on the charge that is left in the battery.

What Can I Do if The Battery Light is On?

The smartest thing to do is to try and get your car home or to a mechanic’s garage as quickly as possible if you see the battery light go on. If you are not in a position where you can do this, the first thing is to ensure that you keep the engine running. Do not turn it off for any reason. If you turn off the engine, it’s likely that you will not be able to start the car again without a jump, and if you’re in an area where you don’t have easy access to mechanics, you probably won’t have easy access to a jump, either.

You will also want to make sure that you turn off any features of the car that draw on electricity unnecessarily. This means turning off the air conditioning, stereo, potentially dimming the dome lights, and try not to roll your windows up or down if your car has power windows. If you have any external devices plugged into your car, like cell phones, make sure that they are unplugged. If it is dark, make sure to keep your headlights on for as long as possible, as driving with them off is dangerous.

How Do I Fix The Battery Light?

Probably one of the more common and easy-to-fix issues if your battery light comes on is a corroded battery cable. Sometimes battery cables also come loose. You can check your battery to see if this is the issue; if it is, the solution is to either clean your connections and retighten or replace the cables. If this is not the case, you can remove your alternator and bring it to AutoZone for free testing. It’s possible that your car might need a replacement alternator belt, or perhaps the belt just needs to be tightened or loosened. If this is not the case, then you may need to replace the alternator. Your battery may also be at fault. If the plates or cells in your battery are damaged, you may need a new one.

No matter what, it’s important to look at your car or get it looked at once you see the battery light flick on.

Advice, how-to guides, and car care information featured on AutoZone.com and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

FREE Loan-A-Tool® program requires returnable deposit. Please note that the tool that you receive after placing an online order may be in a used but operable condition due to the nature of the Loan-A-Tool® program.