History of the battery his iron scalpel, the leg twitched. Galvani believed the energy that drove this contraction came from the leg itself, and called it "animal electricity". However, Alessandro Volta, a friend and fellow scientist, disagreed, believing this phenomenon was caused by two different metals joined together by a moist intermediary. He verified this hypothesis through experiment, and published the results in 1791. In 1800, Volta invented the first true battery, which came to be known as the voltaic pile. The voltaic pile consisted of pairs of copper and zinc discs piled on top of each other, separated by a layer of cloth
Electric battery "secondary cells", or "rechargeable batteries", must be charged before first use; they are usually assembled with active materials in the discharged state. Rechargeable batteries are (re)charged by applying electric current, which reverses the chemical reactions that occur during discharge/use. Devices to supply the appropriate current are called chargers. The oldest form of rechargeable battery is the lead–acid battery, which are widely used in automotive and boating applications. This technology contains liquid electrolyte in an unsealed container, requiring that the battery be kept upright and the area be well ventilated to ensure safe dispersal of the hydrogen gas it produces during