Any energy-storage device allowing release of electricity on demand. It is made up of one or more electrical cells. Primary-cell batteries are disposable; secondary-cell batteries, or accumulators, are rechargeable. Primary-cell batteries are an extremely uneconomical form of energy, since they produce only 2% of the power used in their manufacture.
The common dry cell is a primary-cell battery based on the Leclanché cell and consists of a central carbon electrode immersed in a paste of manganese dioxide and ammonium chloride as the electrolyte. The zinc casing forms the other electrode. It is dangerous to try to recharge a primary-cell battery.
The lead–acid automobile battery is a secondary-cell battery. The car’s generator continually recharges the battery. It consists of sets of lead (positive) and lead peroxide (negative) plates in an electrolyte of sulfuric acid (battery acid).
The introduction of rechargeable nickel–cadmium batteries has revolutionized portable electronic newsgathering (sound recording, video) and information processing (computing). These batteries offer a stable, short-term source of power free of noise and other electrical hazards.
Some electronic machines now have batteries with anodes made of lithium. These batteries can hold their charge for up to five years; they cannot, however, be recharged. In contrast, new lithium ion batteries have anodes of carbon and cathodes made of a compound of lithium, cobalt, nickel, and manganese, together with an electrolyte made of a mixture of propylene carbonate and diethyl carbonate. The battery delivers 3.6 volts compared with 1.2 volts from nickel–cadmium batteries and can be recharged up to 1,200 times.
Two or more cells in a container that produce an electrical current when two electrodes within the container touch an electrolyte. In personal computers, batteries are used as an auxiliary source of power when the main power is shut off, as a power source for laptop and notebook computers (rechargeable batteries, such as nickel cadmium, nickel metal hydride, and lithium ion, are used), and as a method to keep the internal clock and the circuitry responsible for the part of RAM that stores important system information always powered up. See also lead ion battery, lithium ion battery, nickel cadmium battery, nickel metal hydride battery, RAM.
A device for storing and discharging electricity; may have several primary or secondary cells arranged in parallel or series; SYN. electric battery. + prikaži više

An electrical device that transforms standard wall outlet electricity (115–120 VAC in the United States) into the lower voltages (typically 5 to 12 volts DC) required by computer systems. Personal computer power supplies are rated by wattage; they usually range from about 90 watts at the low end to 250 watts at the high end.
A separate unit or part of a circuit that supplies power to the rest of the circuit or to a system. + prikaži više