ExtendingThe Life of Your Car Battery

One of the life sources of your vehicle is your car battery. Without it, you won't go anywhere. You want to make sure that this source is running at its peak performance. Here are ways you can lengthen the life of your car battery.

Get to know your battery:

Specifically, make sure you know when it was made and how long it’s likely to last.

Every car battery sold in the U.S. is stamped with the month and year of its manufacture. You’re looking for the first two characters in particular: a letter and a number. The letters, starting with “A,” correspond to months starting with January -- so “C,” for example, means March. The number is the last digit of the year, so “8” means 2008.

Sixty months (or about five years) from the born-on date is a rough estimate for normal battery life, but many factors can shift this figure one way or the other. Still, keep that date in mind if your battery starts to show signs of depletion.

Turn off your lights when you get home:

Probably the single most common cause of premature battery depletion is headlights and/or interior lights left on overnight, especially if you tend to be a regular culprit of this practice. Some newer cars have auto-off functionality, but most vehicles on the road still don’t, so it’s important to be careful here.

Use accessories sparingly when the engine is off:

Modern alternators have no problem keeping the battery charged when the motor is running, but if the motor’s off, power-hungry cabin technology can do a number on your battery in short order. A battery without the engine is kind of like a laptop without its plug: you’re on borrowed time, and the more you run that battery down, the less eager it will be to hold a full charge. Accordingly, try to limit the amount of time you spend using powered accessories with the engine off. We know it’s tempting sometimes to leave your passengers in the car with music or a movie playing, but you probably shouldn’t make a habit of it.

Monitor battery performance:

The best sign that your battery’s under the weather is slow “cranking” when you start your car. The usual cheery cranking noise will turn dull and lethargic; you might even find yourself wondering if the car’s going to start at all. The good news is that this doesn’t mean your battery is gone forever. You might be able to recharge it. But you shouldn’t knowingly leave your battery in a depleted state for more than a few days, because lead-acid batteries must constantly be kept near full charge to avoid a malady called “sulfated plates”.

Disconnect or “tend” the battery when parked long term:

If you know you won’t be using your car for a few weeks, it’s advisable to give your battery a rest, too, since a small amount of current continues to flow even if the security system isn’t armed. The old-school approach entails disconnecting the negative battery cable (typically marked by a big minus sign), which certainly helps but has the undesirable side-effect of wiping out all of your electronic settings. A better idea, if you can justify the expense, is to pick up an automatic battery charger, which maintains your battery’s charge and lets you keep all those settings, too.