A battery is an electrochemical cell (or enclosed and protected material) that can be charged electrically to provide a static potential for power or released electrical charge when needed.
A battery generally consists of an anode, a cathode, and an electrolyte.
Common types of commercial batteries and some of their characteristics and advantages are summarized in the following table. Battery types not shown include the Zinc-Air, Flooded Lead Acid, and Alkaline batteries.
|Battery Type||Characteristics||Typical Uses||Advantages|
|Sealed Lead Acid (SLA) battery||Can hold a charge for up to 3 years||Backup emergency power source||Inexpensive|
|Nickel-Cadmium (Ni-Cd) battery||Fast, even energy discharge||Appliances, audio and video equipment, toys; most popular batter||Relatively inexpensive; widely available|
|Nickel-Metal Hydride (Ni-MH) battery||Typical power capacity i1.2 V - 1200 to 1500 mAh; extended life 2300 mAh; 2.5 to 4 hours battery life||Portable computers; cellular phones; same as for Ni-Cd batteries||No memory effect; unused capacity remains usable|
|Lithium Ion (Li-Ion) battery||Stable and safe; highest energy capacity||Portable computers; cellular phones; same as for Ni-Cd batteries||Twice the charge capacity of Ni-Cd; slow self-discharge|