Accumulator

An accumulator is a device or component that collects and stores energy, material, or data by accumulating it over time. The term is used in several technical fields with distinct meanings but a common idea of storing a resource for later use.

In electrical engineering and consumer electronics, an accumulator commonly refers to a rechargeable energy storage device, especially a lead‑acid battery. In British usage, accumulators contrast with non-rechargeable primary cells, whereas American usage tends to prefer the word battery. Modern devices rarely use the term, but accumulators appear in historical equipment and some specialized applications.

In hydraulics and pneumatics, a hydraulic accumulator stores potential energy by compressing a gas or spring with pressurized fluid, to smooth out pressure fluctuations, provide peak flow, or supply emergency power. These devices help manage energy delivery in fluid systems and can improve performance and reliability.

In computing, an accumulator is a register or memory location that aggregates a running total or other value during computation. It is used in CPUs and programming languages to accumulate sums, products, or bitwise results through loops and iterative processes. The accumulator pattern describes repeatedly updating a single variable with successive inputs until a final result is produced.

In data processing and streaming contexts, accumulators tally events or counts as data flows through a pipeline, or hold intermediate results for later reduction. Across domains, accumulators provide a simple, centralized means to store and reuse incremental contributions until they are needed.