Battery service comes up when your car's service light comes on, indicating a problem with the electric system. The battery is the first thing to check, as it is the most common problem. In addition to testing the battery to confirm it needs replacement, it's worth taking the time to determine the underlying cause. It might be a dead battery that no longer holds a charge properly. It's worth checking to make sure the alternator is working properly, all the connections are secure, and there isn't a parasitic drain causing the battery to go dead when the vehicle isn't running.
There are two reasons a battery can stop working properly. The first is simply the age of the battery, even though it is designed for such use it can only handle a finite amount of discharge and charging cycles. The second reason is that after a battery is fully discharged, it won't recharge efficiently afterward. Common causes of full discharge are leaving the lights on, having the alarm go off when you aren't aware of it and turn it off quickly, or running the radio and other accessories extensively when the car isn't running. In theory, the battery should only be used briefly to start the vehicle, then the alternator runs the electric system and recharges the battery. If the starter has to run for extended periods before the engine turns over, this can also cause a battery to be drained.
What Might Happen if Battery Service Is Ignored
Once the battery is dead, the car won't start without an external battery to jump start it. This process will get the engine and alternator running so the car can drive until turned off again. Eventually, there will be an utter battery failure and the car won't run at all, even with an external power source, because the dead battery will interrupt the flow of current through the electrical system. A bad battery can also make other electric components act sporadically or blow fuses.
Although a dead battery is something easily replaced from a parts store, the underlying problem won't be identified by such a repair. At Volkswagen of Inver Grove, serving Minneapolis, MN, we conduct a thorough inspection to assure the new battery is going to get the car running again without further problems.