Dear Tracy,

What, if any, maintenance should be performed on car batteries? Do batteries run out of charge more quickly in winter? With the cold weather moving in, I want to make sure I don’t get stuck in the cold with a dead battery.

Stacy D.

Dear Stacy,

Before the winter driving season arrives in full force, it is a good idea to take your car in for maintenance and inspection. Your mechanic can test your battery and if necessary, clean the battery tray and terminal posts. Your shop may also spray the terminals with a protectant to inhibit corrosion. In addition to battery maintenance, the mechanic can inspect your alternator and starting system to make sure everything related to your car’s battery performance is in good order.

While your car battery does not actually drain faster in the winter, extreme cold does have an effect on battery performance. Cold temperatures greatly reduce the effectiveness of chemical reactions within the battery and also increase the battery’s internal resistance. As the temperatures fall, these factors cause a reduction in cranking power. Vehicles need an increased amount of cranking power in cold weather because motor oil is thicker and makes engines harder to crank.

To reduce your chances of being stranded, remember to watch for the signs of a low or dying battery. If the starter turns slowly, your battery could be failing or you may have alternator wiring problems that prevent the battery from fully charging. Another sign of trouble is if your headlights look dim at idle and but become brighter when you accelerate the engine. Finally, if you have any concerns about your battery, look for a purchase date on the battery itself. The battery case should have a decal stating its expected life. If it’s getting close to the end of this expected service life, replace it.