Estimating the Age of an Alkaline Battery

An alkaline battery cannot last forever; but the life expectancy can vary. There are several ways to tell how long the battery will have left. When discussing the lifetime expectations of batteries, you have to consider three main categories. The shelf life is how long a battery can go unused before it loses its power. The use life is how long it will last when being used to power something. This can be affected by a number of different variables, such as the drain of the device it is powering, as well as the capacity (mAh) of the battery. The last category has to do with rechargeable batteries- measuring how many times they can be recharged. All three of these factors will determine how long and how well a battery can last for you.

Step 1 – Shelf Life

Shelf life will vary, depending on the type of battery, and temperature it is stored in. Extreme hot or cold temperatures, such as in a freezer or a car’s glove compartment, will decrease the overall life of the battery drastically. Packaged batteries should be stored at 40 to 50 degrees Fahrenheit. Most battery packages will have a date code on them indicating the use by date. This date is typically the two digit month and four digit year that the battery will be good until.

Step 2 – Use Life

How long a battery in use will last is determined by the following equation. The capacity of the cell is divided by the current drain, and then multiplied by 0.07 to produce the estimated life of the battery. The factor of 0.07 is to account for other variables such as temperature. The internal chemical components of a battery are what lead to a battery losing power over time until it no longer produces the power needed. Even in ideal operating conditions with a perfect temperature, a battery will still lose power over time, and eventually stop working.

Step 3 – Recharge Life

Charging a battery is broken down into three main components as well, consisting of charging, stabilizing, and terminating. Once a battery is charged to capacity, it can began to damage the battery and shorten the life cycle if it remains on the charger. The best method is to be able to remove the battery from the charger once it is charged to capacity but before it begins to be damaged. More batteries are damaged by inappropriate charging than by all other causes combined. More advanced chargers have electronic sensors that will indicate when a battery is charged to capacity so you can remove it from the charger to prevent damage. There are different options for charging the batteries. Some quick methods can fully charge a battery in under an hour while the more common chargers take a few hours or even overnight to charge fully. The speed the battery charges will not have any effect on the performance of the battery or its life expectancy.