Understandind Batteries

Understandind Batteries

BATTERY TECHNICAL

Understanding Battery Shelf Life

Battery shelf life is the length of time a battery can remains in storage without losing its capacity.Even when not in use, batteries age. The battery’s aging is generally affected by three factors: the active chemicals present in the cells, the storage temperature and the length of time it remains idle.

During storage, batteries self-discharge and their contents are prone to decomposition. Higher temperatures make battery self-discharge faster, and cooler temperatures decrease the self-discharge rate. Electrolyte, a chemical in batteries containing high concentration of ions, may permeate through the seals. This causes the battery to dry up and become unusable.

Different Types of Batteries and Their Shelf Life

The diagram below lists popular battery varieties, their self-discharge rate and the temperature range in which they work best

Battery TypeSelf-DischargeTemperatureShelf Life In Years
Nickel Metal HydrideSlow-Medium
(retains 75% after 1, 2, or 3 years depending on brand)
-4F° to 122° F
(-20° to 50° C)
5 Years
Nickel-ZincFast
(loses 13%/month)
-4° to 140° F
(-20° to 60° C)
1 Year
Nickel CadmiumFast
(loses 10% in 1st 24hrs, then 10%/month)
22° to 140°F
(-30° to 60°C)
5 Years
Rechargeable AlkalineVery Slow
(<0.5%/month)
-4° to 140°F
(-20° to 60°C)
4-7 Years
AlkalineVery slow
(retains 80% capacity after 5-7 years)
0-131°F
(-18° to 55°C)
10 Years
LithiumVery slow
(loses 0.6% per year)
-40° to 140°F
(-40° to 60°C)
7-15 Years
Carbon Zinc / Zinc ChlorideFast0° to 130°F
(-18° to 55°C)
2-3 Years

In some cases, freezing the battery can reduce its self-discharge rate. Nickel Metal Hydride types for example, can be refrigerated for several months and only drain 10% o. However, there are battery types with slow discharge rate, no matter what their storage condition is. Rechargeable Alkaline and Alkaline Batteries, Lithium and Carbon Zinc / Zinc Chloride are among the batteries which possess longer shelf-life.