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.

Second, the battery light is probably one of the most misunderstood lights in your vehicle because most people immediately assume it means your battery is bad. While your battery can be bad in some of these cases – that is not why the light is on. The light is on because your alternator is not properly charging. Initially, in the olden days, this light was referred to as the generator light and often had the abbreviation “GEN” on the light itself. Several made the migration to “ALT” but eventually, this light became a little battery icon, or battery word, and the rest is misunderstood history.

What you need to know though is that the battery light does not mean your battery is bad. It does mean, if you don’t attend to it quickly, your battery will die, because your entire car’s electrical system is running off of it.

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 the battery charged and thus, the car is running on battery power only. Basically, if you see the battery light on in your car when it is running, you shouldn’t expect to be able to drive it for very long. Think of it like unplugging your cell phone from your wall charger. If you leave it plugged in, your phone will last indefinitely on 100% charge. Unplug it, and you’re on battery power. Chances are good that after a day, your phone will be dead.

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 to an hour of driving. This is about how long it takes most car batteries to completely discharge to a level that the ignition system cannot keep the car running. Of course, this depends on your battery and your car, and some cars may be able to last longer while others may die quicker.

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.

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.

Understand that driving with the light on can cause issues with your battery in the long run, most notably the rapid discharging can cause your battery to also go bad, and not be able to be recharged. Many customers end up replacing the alternator in the car, don’t properly recharge the battery before installation, then find out the battery also went bad. Just remember that driving on the battery light is limited time. Get the alternator or wiring fixed, and properly recharge the battery at the same time.

The folks at AutoZone can always help with battery and charging system issues, both on the car, and with the parts off the car. If you need a shop to help with your repair, search through our Preferred Repair Shops in your area to help you get your car back running again!

Advice, how-to guides, and car care information featured on 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.

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