Understanding What a Car Battery Indicator Light Means

January 27, 2012

Your car battery indicator light has come on in your car, but what does it mean? There are a few things that could be going wrong in your vehicle.

Faulty Battery

A common reason for a battery indicator light to come on is a faulty battery. If a battery cannot receive a charge because it has a bad cell, this will cause the voltage to drop and a light to come on. This is probably the easiest of the reasons to repair.

Faulty Alternator

Another common reason for a battery indicator light is a faulty alternator. A car is designed to run on twelve volts, but it also needs enough power to charge the battery as you drive. The optimal amount of charge from an alternator is between 13.6 and 14.6 volts. If it begins to near the 12 volt mark, the light will come on and the computer may shut down unnecessary processes, causing lowered performance of the vehicle. At this point the alternator will need to be either replaced or rebuilt.

Faulty Wiring

A last common issue is faulty wiring or excessive resistance. If a wire has become severed partially or completely, the flow of electricity is interrupted, causing the light to come on. Another interruption in the flow is buildup on the battery terminals. Buildup on the terminals is easily prevented by adding a coat of anti-corrosive on the terminals after you have cleaned them. The wiring issue can become a little more difficult and you should allow a professional to look at your vehicle before you attempt any repairs.

Now that you know some common causes of the battery indicator light, run some tests and determine what your cause is.