Battery (electricity)

:For other uses, see battery (disambiguation).

Common battery types

From a user's viewpoint, at least, batteries can be generally divided into two main types - rechargeable and non-rechargeable (disposable). Each is in wide usage.

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Disposable batteries, also called primary cells, are intended to be used once, until the chemical changes that induce the electrical current supply are complete, at which point the battery is discarded. These are most commonly used in smaller, portable devices with either low current drain, only used intermittently, or used well away from an alternative power source. See also: waste.

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By contrast, rechargeable batteries or secondary cells can be re-charged after they have been drained. This is done by applying externally supplied electrical current which causes the chemical changes that occur in use to be reversed. Devices to supply the appropriate current are called chargers or rechargers.

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The oldest form of rechargeable battery still in modern usage is the wet cell lead-acid battery. This battery is notable in that it contains a liquid in an unsealed container, requiring that the battery be kept upright and the area be well-ventilated to deal with the explosive oxygen and hydrogen gases which are vented by these batteries during overcharging. The lead-acid battery is also very heavy for the amount of electrical energy it can supply. Despite this, its low manufacturing cost and its high surge current levels make its use common where the weight and ease of handling are not concerns.

Related Topics:
Lead-acid battery - Oxygen - Hydrogen

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A common form of lead-acid battery is the modern car battery. This can deliver about 10,000 watts of power at a nominal 12 volts (although the true open-circuit voltage is closer to 13.7 V) and has a peak current output that varies from 450 to 1100 amperes. The battery's electrolyte is sulfuric acid, which can cause serious injury if splashed on the skin or eyes.

Related Topics:
Car - Watt - Volt - Ampere - Sulfuric acid

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A more expensive type of lead-acid battery called a gel battery (or "gel cell") contains a semi-solid electrolyte to prevent spillage. More portable rechargeable batteries include several "dry cell" types, which are sealed units and are therefore useful in appliances like mobile phones and laptops. Cells of this type (in order of increasing power density and cost) include nickel-cadmium (nicad or NiCd), nickel metal hydride (NiMH), and lithium-ion (Li-Ion) cells.

Related Topics:
Mobile phone - Laptop - NiCd - NiMH - Lithium-ion - Li-Ion

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