The battery plays an essential role in the function of modern-day cars. It's responsible for providing the power needed for your car's electrical systems to function. Without a functional battery, your car's engine, lights, air conditioning, stereo and other electrical systems won't turn on. A typical car battery, however, only lasts about five to six years, after which it must be replaced. So, what causes car batteries to fail in such a short period of time?
Heat can shorten the lifespan of your battery, causing it to fail prematurely. A study conducted by BCI found that the average lifespan of car batteries in extremely hot climates was just 30 months -- significantly shorter than the five- to six-year average for all batteries. Unfortunately, there's not much you can do to protect your car battery from heat. If you live in a hot climate, it will naturally be exposed to heat, thus shortening its lifespan.
Another common reason why car batteries fail is corroded connectors. The connectors must make direct contact with the battery posts. Otherwise, electricity won't be able to flow from the battery to your car's electrical systems. If you didn't tighten the connectors all the way, there might be enough "wiggle room" for a connection failure to occur. However, this may also occur when the connectors have developed rust. As rust forms over the connectors, it prevents electricity from flowing to your car's electrical systems.
When the alternator fails, it can affect the performance of your battery, shortening its lifespan and even preventing it from holding a charge. This is because the alternator works in conjunction with your car battery. When your car is running, the alternator will recharge the battery so that it doesn't die. But if the alternator fails, the battery will lose its charge. Therefore, you should test both your battery and alternator if you are experiencing electrical problems with your car.
A lesser-known cause of battery failure is parasitic drain. This phenomenon occurs when one or more electrical systems or devices constantly pulls power from the battery, even when the car's ignition is turned completely off. Examples of parasitic drain may include leaving the overhead light on, leaving a device plugged into your car's charging port, or failure to use a remote wire when connecting a stereo amplifier to the battery.