How long do AA batteries last?

The AA battery is one of the most common battery sizes used by consumers today. Exactly how many hours of use can be expected with an AA battery?

Unfortunately, there is no exact or consistent value that can be provided to answer this question. A battery's life is drastically altered based on many factors: what type of battery it is, the manufacturer of the battery, the amount of "drain" or "draw" a device needs from the battery, and so on. If you know approximately what a battery's capacity is and how much drain from the battery a device needs, then you can get a good idea of how long a battery will last powering that device.

Alkaline AA batteries are the most common type of AA battery, so some of the information in this article is more specific to the Alkaline battery type.

A battery's capacity is measured in ampere-hours (Ah). Often this capacity measurement is expressed with the Ah sub-unit: milliampere-hour (mAh). One milliampere is 1/1000th of an ampere... but let's not get too technical. It is easier to say that 1000 mAh is the same value as 1 Ah.

The exact capacity of an AA battery will vary based on the manufacturer. Typically, an Alkaline AA battery will have a capacity ranging from 2000-3000 mAh. In rough terms, a battery with a capacity of 3000 mAh can supply a device drawing 1 mA for 3000 hours - before needing replacement. Of course there are other factors for a battery's life than just its capacity and how much a device is draining from it, but this gives you a general idea of what to expect from a battery. Notice that a device with a higher "draw" will shorten the life of a battery. In this example, the device was drawing 1 mA. If a device was drawing 1000 mA, the battery's life would not be much more than a couple hours.

If exposed to extreme temperatures (hot or cold) for an ample amount of time, a battery's life expectancy will be shorter. Even if you do not use a battery at all, they tend to lose 8 to 20 percent of their original charge every year!

Here are a few practical examples of how long AA batteries can appoximately last:

In a TV remote that is used every day - about one year.
In a radio that is used an hour a day - about three months.
In an xbox video game controller - about twenty-five hours.
In a Game Boy video game device - about ten hours.