battery [ME] The root of battery is Latin battuere ‘to strike, beat’, and originally referred to metal articles shaped with a hammer or to fighting. The military adopted the term to mean a succession of heavy blows inflicted upon the walls of a fortress with artillery, and so it came to have the sense ‘a number of pieces of artillery combining in action’ [M16th]. It is this idea of combining to produce a result that is behind the use in electrical batteries. The original electrical battery was a series of Leyden jars, glass jars with layers of metal foil on the outside and inside, used to store electric charge. Benjamin Franklin (1706–90) mentioned the device in a letter of 1748. Sir Humphry Davy (1778–1829) developed the later galvanic battery (named after the Italian physicist Luigi Galvani (1737–98)), using chemical action to produce electric current, and described it in 1801. An electrical battery is a container with one or more cells, and this no doubt prompted the use of the word for a series of cages for laying hens [M20th].