Physics:18650 battery

From HandWiki
Short description: Cylindrical lithium-ion battery
  • 18650 battery
  • 1865 cell
Lithiumion-laptop-battery-internals.jpg
Panasonic 18650 batteries inside a laptop. Each cell has a capacity of 2450 mAh.
TypePower source
Working principleElectrochemical reactions, Electromotive force
First production1994
Pin configurationAnode and Cathode
Electronic symbol
Battery symbol1

An 18650 battery[1] or 1865 cell[2] is a cylindrical lithium-ion battery common in electronic devices. The batteries measure 18 mm (0.71 in) in diameter by 65 mm (2.56 in) in length, giving them the name 18650.[3]

Panasonic first developed the 18650 battery in 1994 "when there was a growing need for ever smaller and lighter storage batteries that could be used for ever longer periods of time".[4] They are now commonly used in power tools, electric bicycles, laptops, and electric vehicles.[5]

Chemistry

18650 batteries are most commonly lithium-based, although sodium-ion variants are available for purchase.[6] Lithium-ion batteries consist of an anode, typically made of graphite and a cathode, often of lithium-metal oxide.

Packs

A generic BMS for 4 series lithium-ion cells ('4s BMS')

18650 batteries are more commonly used in packs, where a BMS (Battery Management System) is required, especially once cells age and perform differently. BMS boards balance the voltage of cells in series and protect against over- and under-discharge.

See also

References