A DELL laptop battery , which is actually an electric cell, is a device that produces electricity from a chemical reaction. Strictly speaking, a battery consists of two or more cells connected in series or parallel, but the term is generally used for a single cell. A cell consists of a negative electrode; an electrolyte, which conducts ions; a separator, also an ion conductor; and a positive electrode.  Dell Inspiron 9400 battery , Dell 310-6321 battery , Dell 310-6322 battery , Dell D5318 battery The electrolyte may be aqueous (composed of water) or nonaqueous (not composed of water), in liquid, paste, or solid form. When the cell is connected to an external load, or device to be powered, the negative electrode supplies a current of electrons that flow through the load and are accepted by the positive electrode. When the external load is removed the reaction ceases. Compaq 319411-001 battery , Compaq Presario 2100 battery , Compaq Presario 2500 battery A primary battery is one that can convert its chemicals into electricity only once and then must be discarded. A secondary battery has electrodes that can be reconstituted by passing electricity back through it; also called a storage or rechargeable battery, it can be reused many times.

One of the first space  Sony PCGA-BP2R battery , Sony PCGA-BP2S battery , Sony PCGA-BP2T battery , Sony PCGA-BP2V battery   was the Silver-Zinc battery, which dominated the industry in the 60's. This is a premium system with very high specific power and energy, but is quite expensive due to the use of silver. They are still used in selected applications, such as launch vehicles (rockets) and torpedoes. Mars Pathfinder also used a Silver-Zinc battery, but it was designed to be rechargeable. They have a relatively short cycle life, and are not used for multi-year missions. This type of battery is used commonly in the commercial market as hearing aidbatteries.

Batteries come in several styles; the most familiar are single-use alkaline batteries. NASA spacecraft usually use rechargeable nickel-cadmium or nickel-hydride batteries like those found in laptop computers or cellular phones. Engineers think of batteries as a place to store electricity in a chemical form.

Battery technology is part of the power system, storing and discharging energy on each orbit of the spacecraft. The  PA3166U-1BRS , PA3331U-1BRS , PA3098U-1BRS , PA3084U-1BRS , PA3399U-1BRS , PA3395U-1BRS help provide a constant source of power to the spacecraft by storing energy when excess is provided by the solar cells and discharging stored energy when the solar cells are not providing any during periods of eclipse.