How to Tell How Old a Car Battery Is

A car battery's lifespan escapes a car owner's consideration until the battery fails and renders the vehicle immobile. Often, this occurs at the most inopportune time and requires a call to roadside assistance and a tow to a service garage. Upon replacement, it's essential to keep in mind that most car batteries are useful for a period of three to five years. Keep this in mind so that you remain aware of the age of your car's battery.

Battery Age

How to Tell How Old a Car Battery Is

There are several ways to determine the age of a car battery. The simplest is if you bought your car new. A brand new car has a brand new battery. So, your battery's age will be the same as the time elapsed since you bought the car.

Another straightforward way to determine battery age is to buy the battery new, as a replacement for one that went bad. In this case, you can just refer to the original receipt for the date of purchase. If the receipt does not exist, a dealership or auto parts store may have a bill of sale on record and can provide the purchase date.

However, many people buy used vehicles, which means they can't determine the battery's history or age unless the previous owner provided the documentation. In those cases, there is a more methodical approach to finding out when the battery was manufactured and shipped to the wholesale distributor.

The first step is to locate the battery under the hood and look for a sticker with date information printed in a recognizable convention. For example, "3/15" would simply mean the battery was manufactured in March 2015.

If there is no date sticker, the battery will have a strip, engraving, or heat stamp with a decipherable alphanumeric code. Typically found on the battery cover and sometimes on the battery itself, this code can be several characters long, giving the date information in the first two characters in the sequence. The first character will be a number from zero through nine that corresponds to the last digit in the year in which the battery was manufactured. For example, a five would mean 2015. The second character is a letter that refers to the month the battery was made. The letters A through L directly correspond to January through December. For example, the letter 'C' would mean March. Putting it together, "5C" indicates a manufacturing date of March 2015. These characters can be interchangeable, so "5C" and "C5" mean the same thing.

If there is no code on the battery, you'll need to estimate its age based on appearance. The amount of corrosion on and around the terminals is an indicator of age. The more of it there is, the older the battery is.

Battery Failure

The most common sign that a battery may need replacement is a slower than normal engine crank phase when you try to start it. It will sound as if the engine is struggling to start. If you notice this, you can also check battery strength by turning on the headlights while the car is off. Dim headlights are an indicator that the battery may be approaching the end of its life.

However, there are times when the battery fails due to cold temperatures or if you don't drive the car for a long time. These are not necessarily indicators of a dying battery. A jump start can rejuvenate the battery and bring it back to its normal strength level in those cases. But if the battery is old and weak, a jump start is not the solution. It may start the car for the moment, but the battery will likely fail again soon.

Battery Test

Whether the battery is getting old or there is evidence of imminent failure, getting a battery tested every six months after the three-year mark is a good idea. A battery test is usually a free service offered by an auto parts retailer or an auto service club such as AAA. A quick and simple reading will let you know if your battery is still running strong or needs replacement. Due to corroded connection points and the battery's weight, consider professional installation with proper disposal of the old battery over a self-installation.