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] The battery comes in many nominal voltages depending on the specific chemistry used.
 Panasonic 18650 batteries inside a laptop. Each cell has a capacity of 2450 mAh. | |
| Type | Power source |
|---|---|
| Working principle | Electrochemical reactions, Electromotive force |
| First production | 1994 |
| Pin configuration | Anode and Cathode |
| Electronic symbol | |
 | |
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.[citation needed]
By 2023, some sodium-ion variants were available in the 18mm x 65 mm cylindrical cell form factor as well.[6][better source needed]
Packs
18650 batteries are commonly used in packs, where a battery management system (BMS) 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.
Products using 18650 cells
18650 battery cells are used in a wide variety of products from the 1990s through the 2020s, and is widely regarded as the most produced lithium-ion cell size.[7] 18650/1865 cells are used in many laptop computer batteries, cordless power tools, many electric cars, electric scooters,[8] most e-bikes, older portable powerbanks, electronic cigarettes,[9][10] portable fans, and LED flashlights. Nominal voltage is 3.6-3.7 V.[11][5]
In the electric automobile sector, they are used in the first three vehicles manufactured by Tesla, the first-generation Roadster (late 2000s), Model S (2012+), and the Model X (2015+).[12]
See also
