A
rechargeable battery,
storage battery,
secondary cell, or
accumulator is a type of
electrical battery which can be charged, discharged into a load, and recharged many times, while a non-rechargeable or
primary battery is supplied fully charged, and discarded once discharged. It is composed of one or more
electrochemical cells. The term "accumulator" is used as it
accumulates and
stores energy through a reversible
electrochemical reaction. Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to
stabilize an electrical distribution network. Several different combinations of electrode materials and electrolytes are used, including
lead–acid,
nickel cadmium (NiCd),
nickel metal hydride (NiMH),
lithium ion (Li-ion), and
lithium ion polymer (Li-ion polymer).