accu

Accu is a common shorthand for accumulator, a device that stores electrical energy chemically and can be recharged. In Dutch and Flemish, the term accu is the standard word for a rechargeable battery. In German-speaking regions, the equivalent colloquial form is Akku. In English, accu appears mainly in historical usage or as a brand name rather than as everyday language.

Etymology and definition: The word accumulator derives from the Latin accumulate, through French accumulateur, referring to a device that accumulates and stores energy. In practice, an accu is a rechargeable energy storage device used in a wide range of electrical equipment, from small consumer devices to vehicles and power systems.

Usage and context: Accu typically denotes a rechargeable battery, as opposed to a non-rechargeable primary cell. While “battery” can be used generically in English, many languages distinguish rechargeables with terms like accu or Akku. In automotive and industrial contexts, the term accumulator has historical usage for lead-acid car batteries, though today Akkus and accumulators span many chemistries, not limited to a single type.

Chemistries and examples: Common accu chemistries include lead-acid, nickel–cadmium (NiCd), nickel–metal hydride (NiMH), and lithium-ion (Li-ion). The underlying principle is reversible electrochemical reactions that allow energy to be stored and returned upon discharge, followed by recharging.

See also: Battery, Accumulator, Akku, Batterie, Battery terminology.