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Why Is My Car Battery Light on While Driving? 

Why Is My Car Battery Light on While Driving? 

Just about all modern vehicles on our roadways today, have a 12-volt battery that can be recharged. The vehicle battery is one that provides the needed energy to just about any and every electrical component of the vehicle. From the ECU (the engine control unit), to the ignition system, radio, interior lights, headlights, and more, you need your battery! So, should it fail you’re left with an inoperable car. 

Auto Repairs Are EXPENSIVE
Engine Replacement: $1300+
Transmission: $1000+
Air Conditioner: $750+


 

Back in the “olden days”, there were two ways a car owner could test a car battery. One way was to test the voltage of the car battery. The other way was to wait until their headlights would begin to flicker. Nowadays, lots of modern cars, SUVS, crossovers and other vehicles have a battery light that illuminates once the vehicle’s computer system detects a battery charging issue. 

 

“So Why is My Car Battery Light on While Driving?” 

There are so many reasons which can cause the vehicle battery light in the car to illuminate while the driver is operating the vehicle. Below are some of the most common reasons, so that you can diagnose the problem.  

 

There’s Corrosion At The Battery Terminals 

Corrosion at battery terminals is a very common issue and one that won’t cost lots of money to remedy. Corrosion usually makes its “guest appearance” on your battery, once hydrogen gas has been released from the sulfuric acid inside the car battery. Corrosion also makes itself known by giving you a difficult time, as you work to start your car. Many times, battery corrosion that’s found on the terminals or the battery posts can interrupt the flow of electricity. That corrosion will furthermore hamper the alternator from doing its job. All of this may result in your battery light coming on and staying on, well after you start your vehicle. Do see a whiteish, or a grayish powdery substance around the battery cables? Then that is battery corrosion.  To fix this, just disconnect your battery cables. You can then use some baking soda, water and a steel brush to remove the battery corrosion and clean your battery posts.  

 

Your Battery is Weak 

Another reason that your car battery light is on, is because your battery is weak. How old is your battery? When was the last time you replaced your battery? Generally, batteries tend to weaken a lot faster in hotter temperatures. So, if your battery is on “death’s door”, then your battery light will be illuminated on your dash, to irritate you and notify you that it’s time for a replacement. Although car batteries are sold with warranties, those warranties have various lengths. So, you want to check your warranty. Depending on the length of the warranty and the time that the battery dies, you may be able to get a free battery. So, hold on to all receipts and warranties after you buy a car battery. You may even be able to receive a pro-rated credit toward a brand-new battery. To confirm that you indeed have a bad battery, grab a battery multimeter so that you can test its voltage. Then, connect the battery’s negative lead to the negative battery terminal while connecting the red or the positive lead to the positive battery terminal. Your voltage reading should be somewhere between 12.4 and 12.7 volts. If you got a lower reading than 12.2 volts, then you may need to replace that battery. 

 

A Battery Cable May Be Loose 

While a corroded battery terminal can cause a partial connection, a loose battery cable or one that just isn’t connected tight enough can cause your vehicle battery light to illuminate on your dash, while you’re driving. Sometimes, this can happen after you hit a pothole or a huge bump in the road.  To remedy this issue, just ensure that your battery terminal is seated as far as it can possibly be seater.  Then take a socket or a wrench and take the time to tighten the nut on each terminal, till it stops turning. Don’t forget to clean off any corrosion that you may have, before tightening.

 

There is a Faulty Alternator 

Typically, car alternators last about seven years, or up to 120,00 miles. The alternator has the task of keeping the car battery fully charged as you drive. But should you have a faulty alternator, then your battery will not work as it should. This can result in your car battery light coming on while you’re driving. 

When your alternator completely dies, the power that resides in your car battery will be exhausted fast. 

 

Faulty Alternator Belt 

Not only will a bad alternator cause your battery light to come on while driving, but a bad alternator belt-which connects the alternator and the crankshaft together-will cause your battery light to come on. Whether your alternator belt is torn, frayed or loose, your alternator won’t be able to work properly. This can cause your battery light to come on.  A replacement of your alternator belt is the best option to fix the issue. 

 

Too Many Car Accessories 

If you have checked your battery and it has the proper voltage, and your alternator is in good working order, then you may want to look at the accessories you have charging in your car.  What is utilizing power in your vehicle? Are you charging your smartphone, along with an iPad, or some other mobile device? If your vehicle’s charging system isn’t working optimally, then now is a good time to check the number of items you have that are sitting the seats of your vehicle, charging. As you charge all of your mobile technology, it is important to remember that your vehicle’s power steering, heating, A/C and other components STILL require power to work. Once you begin adding mobile accessories in the mix such as a mobile GPS system, a smartphone, an iPad, laptop and other items, then you’re talking about more power that has to be used. 

 

Can You Drive Your Car With The Battery Light On?

Driving with your car battery light on is not good to do. Clearly there is an issue with the battery if the light is on while driving. So, you need to tend to this issue ASAP.  You don’t want to be on the road somewhere and your vehicle loses power. Your vehicle battery gives power to many vital parts of your car. So, no, please do not drive with your car battery light on. 

 

What If My Battery Light Is Off, But Then Comes On While I Am Driving? 

Should you be driving somewhere and you have a battery light on signal, try the following steps. 

First Step 

Begin with turning off everything that is drawing power. If your vehicle battery light is on, then then you still have enough battery left to power the vehicle but probably not for very long.  You also want to make sure that you disconnect any mobile devices such as your iPad, phone or laptop. 

 

Second Step 

Pull over somewhere and stop. If you’re not too far from home, go back home or go to a trusted mechanic’s garage. But home is your best bet. After reaching a destination or home, stop your car and then turn it off.  Are you noticing that the engine temperature is getting warmer or is overheating? Allow it to cool. Did you experience a loss in your power steering?  Then you may be dealing with a broken serpentine belt. Additionally, your water pump and your power steering or alternator may not be operating as they should. If you have reached a safe place and you have unplugged everything as well as turned off your car, then try starting it again. Does the battery light come back on? Don’t drive the car. Turn off the engine and if you can, open the hood and see if your alternator, battery or your serpentine belt have any damage or issue with them. You want to ensure that you turn off your engine, before you do any inspection on your car, or its components. 

 

Third Step 

Now, you can inspect the parts of your car, once the car is cool. Look for fractures, and corrosion on your battery. Do you see corrosion around your battery and the terminals? Take anything that you can- that cannot carry and charge, and clean it off. You may want to have some gloves on, to do this- if you can. After you clean the corrosion, check for any loose cables or terminals. If anything is loose, then you want to tighten it. 

 

Fourth Step 

Now that you have checked your battery and other components, you now want to move to the fuses. If your vehicle’s fuse box is inside the car, then that means it is in the glove compartment or ceiling. There is also a chance that it is located on the left side of the dashboard, right near the floor of the driver’s side.  If you are able to, replace any blown fuses. This may be a reason that the battery is light is on. 

 

Safety Measures And Your Vehicle 

These days, there are safeguards that can be put into place to keep you safe, should you have your car battery light on while driving or just suddenly come on. So, you may want to invest in: 

 

Road Assistance Services 

There is never a convenient time for a battery light to come on. So, if you live alone and have no one to come out and help you, then you may need to invest in a monthly road service assistance plan. Lots of companies can come out to your car, help and get you back home safely. You certainly have to a pay fee, but aren’t you worth it? 

Regular Maintenance 

Whether you have a new car, or an older one, you want to ensure that you get monthly maintenance checks on your vehicle. We realize that all issues cannot be prevented with mechanic checks, but at least you can discuss any issues you see with your car, once you see your auto professional on a regular basis. 

 

Keep your Eye on Your Battery And Replace When Needed 

Another way to prevent that battery light from coming on, is to watch what you plug in your car. Additionally, be sure that you have “healthy” car parts. This means, keep track of when you replace your starter, battery, spark plugs and other essential car parts. You want working car parts in your car at all times. So, keep a car diary if you are not able to remember when you replaced vital car components. 

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