Why Do Car Batteries Die in the Winter?

Car batteries are fickle creations. While they are absolutely essential to your vehicle, they can cause drivers some distress when they don’t work properly because of the weather. This is particularly true in months of extreme temperatures. Although winter may seem to kill batteries at a faster rate than any other month, hot weather has the same effect, and here’s why:

Effects of Cold

Lead acid car batteries are effective in many temperatures, but their performance drops significantly in areas of extreme heat and cold. Some manufacturers estimate that their capacity drops by as much as 20 percent in freezing weather and by around 50 percent when the thermometer sinks to -22 degrees Fahrenheit. This change in capacity means that even a brand-new battery may not be able to produce the amperage necessary to get your starter working. When a battery is older, this problem is compounded.

Effects of Heat

Heat has the same effect for different reasons. In high heat, capacity actually significantly increases, but the life of the battery is cut short. A battery that regularly operates in 77-degree weather, for example, can be expected to last 50 percent longer than those that are regularly exposed to temperatures in excess of 92 degrees. In fact, for every 15 degrees the temperature increases, the life of a car battery is decreased by 50 percent.

Signs Your Battery Is on Its Way Out

If you live in the Arizona area, you should only expect your battery to last two to three years. Any more than that is bonus time. If your battery is nearing that age, be prepared for the day it won’t start. Also, look for the following signs it may be failing faster than you think:

  • Your engine is slow to crank.
  • Your clock and other electrical components aren’t working as usual.
  • The dashboard warning light illuminates.
  • The battery case looks swollen.
  • Unusual smells are seeping from under your hood.

To get the most out of your battery in summer, make sure you store your car in the shade as much as possible. This could be a garage, a covered carport or even under a tree. Although it will only lower the battery’s temperature a few degrees, over time it can make a big difference in expanding the life of your battery. In winter, keeping your battery charged will have the greatest impact.

At Sun Devil Auto, we know getting stuck with a dead battery can be a huge problem no matter what time of year it may be. We offer a free battery inspection and are happy to inspect your battery at any time. Come on by today, no appointment necessary!