Information & Learning Center

Find Batteries a secure, temperature regulated home.The cooler the better.

This is not that junk drawer in the kitchen beside the stove. Junk drawers
generally are full of what their name implies, junk. Junk can contain any
number of things, loose change, uncapped pens, screws... I'm sure you get the idea. But why are these things bad for batteries? They are metal. Batteries are small power cells. Their positive and negative side can connect to form a full circuit and start using their power if a piece of metal closes the connection. You've spent your money on your batteries, you want them to last as long as they can; the average alkaline battery can have a shelf life of over 3 years. Batteries that sit in a draw discharging themselves are going to be of no use when you want them. Batteries function on a chemical reaction within them. If this chemical reaction is occurring while they are stored, the batteries are not going to provide the longevity you want when you start to use them. Their electrical power resides in the movement of electrons during the chemical reaction. Most batteries have a wide range of operating temperatures. Let's use Alkaline Batteries as an example --

 
Specifications for E91 AA Energizer Battery

What we can see from this information is what chemicals are reacting to create power (the current), how strong the power is (the voltage), and about how long during ideal conditions that power will last (capacity).
As you can see, the average household battery can function in some extreme temperatures. They will not perform ideally, but they aren't in danger of malfunction at these levels. If batteries are stored somewhere temperature regularly fluctuates... beside a stove, in an unheated garage, in your car... they run the risk of malfunctioning. Alkaline batteries in particular can leak, this is their chemical components seeping from within their casing. Repeatedly heating and cooling a battery can cause its casing to become brittle or even unsealed which can cause this leakage. Also using a battery when it is very old, under or overcharged, can cause this as well.

 
Store Batteries with their contacts protected or all facing the same direction.

Modern batteries are designed to function when a full circuit is made using specific part of their casing, their end caps or contacts. For this reason protecting those contacts will ensure your batteries are not discharging their power before you are ready to use them. If you are storing multiple batteries in the same location keep them all faced the same way. Keep all the positive contacts on one side so you don't risk completing a circuit between the two batteries.

 
Storing batteries in the freezer or refrigerator doesn't necessarily prolong their life.

Alkaline batteries stored at "room temperature" self discharge at a rate of less than 2% per year. So normally refrigerating or freezing them will only help maintain their charge. However, if alkaline batteries are stored at higher temperatures they will start to lose capacity much quicker. At 85 degrees F they only lose about 5% per year, but at 100 degrees they lose 25% per year. Generally the hotter the climate, the faster your battery will loose its charge.

NiMH and NiCad batteries self discharge at a faster rate than alkaline batteries. These batteries can discharge a few percent of their charge per day. Storing them at lower temperatures will slow their discharge by a lot. Putting a NiMH or NiCad battery in the freezer to preserve its charge can result in having a 90% charged battery available in a months time.
 

Exact Battery does NOT RECOMMEND storing rechargeable batteries while they are charged. Rechargeable will last much longer if stored discharged so you do not have to worry about their self discharge.

" Memory effect, also known as lazy battery effect or battery memory, is an
effect observed in nickel cadmium rechargeable batteries that causes them to
hold less charge. It describes one very specific situation in which certain
NiCd batteries gradually lose their maximum energy capacity if they are
repeatedly recharged after being only partially discharged. The battery
appears to "remember" the smaller capacity. [1] The source of the effect are
changes of the characteristics of the underused active materials of the
cell. The term is commonly misapplied to almost any case in which a battery appears to hold less charge than was expected. These cases are more likely due to battery age and use, leading to irreversible changes in the cells due to internal short-circuits, loss of electrolyte, or reversal of cells. " -- from Wikipedia -- http://en.wikipedia.org/wiki/Memory_effect

Memory effect is actually a battery loosing its storage capacity as it ages or is improperly charged or discharged. This is why Exact Battery will recommend fully charging rechargeable batteries before their first use and using a rechargeable battery to until it is fully discharged. Not doing so will create imbalances within the battery that causes what is referred to as "memory". The battery does not actually remember its previous charge, its actually been altered by misuse to only charge partially.