A battery, sometimes called a cell, is a device that.' converts chemical energy into electrical energy. When two or more cells are joined together in such a way that the currents produced from each flow in the same direction, they are known as a battery of cells. There are two basic types of batteries: the primary, nonrechargeable battery, where the electricity stops when the chemicals are used up, and the secondary (or storage) battery, which can be recharged.
The battery originated with Alessandro Volta (1745-1827) who, in 1799, invented the "voltaic pile," a pile of silver and zinc disks, separated by pieces of fabric saturated with sea water, that supplied an electric current when connected by a wire. His work was based on that of Luigi Galvani, who had noticed that a dead frog's legs twitched when they came into contact with two different types of metal.
Each cell had two terminals, or electrodes—a positive one, the anode, and a negative one, the cathode—suspended in a liquid known as the electrolyte. Over the next few years, a number of inventors developed other combinations of metals and electrolyte to produce more efficient batteries. In the 1880s a solid electrolyte was used and the contents were encased in covers and known as dry cells. The first portable safe device, known as the "Flashlight," was produced in 1896.
In 1859 Gaston Plante, a French physicist, produced a secondary (or storage) battery, which could be recharged and is similar to the battery, or accumulator, that is used in today's automobiles. In this battery, lead plates were immersed in sulfuric acid.
