To help illustrate how a battery works, let’s begin by using a more simple battery like the alkaline. All batteries have a cathode (positive) and an anode (negative) portion of the battery.
The alkaline cathode is a mixture of manganese dioxide, graphite and an electrolyte. This mixture is granulated, aged in storage and then compacted into hollow cylinders called preforms. These preforms are inserted into a steel can. The steel can and mixture now become the cathode, or the positive charge of the alkaline. To keep the material from leaking, an indentation and sealant are used.
The cathode and anode can not come into contact. Therefore, a separator is placed in between the cathode and anode. This separator is soaked with an electrolyte that aids in ionic or electrolytic conductivity once the battery is in use.
The anode (negative) is made of mostly zinc powder and several other material. This is in the form of a gel. This gel is inserted into the steel can against the separator. At this point, the battery could give off a charge. However, the battery would not be able to work for long because it is not sealed.
The seal is made up of a brass nail (the nail acts as the current collector), a plastic seal and metal end cap. The three items are inserted into the steel can against the indentation formed earlier.
What Is The Shelf Life Of A Battery? | |
Silver Oxide: | 2-3 years |
Alkaline: | 4-5 years |
Lithium: | 5-7 years |
NiCad/NiMh: | Will self-discharge 1% – 2% per day, but will fully recover after few charge cycles. Practical shelf life: 5 years. |
Sealed Lead Acid (SLA): | 1 year without charging. Charging every 90 days will extend shelf life to 1.5 – 2 years. |
Automotive: | 6 months without charging. Charging every 90 days will extend shelf life to 1 – 1.5 years. |