The Planté cell was the first application of the principle of polarization to the storage of electrical energy. This consisted at first of plates of lead rolled into a spiral, separated by strips of vulcanite, and acted on by dilute sulphuric acid. Such a cell connected with a battery was found to become energized and to give off a considerable current for several hours. The electromotive force of such a cell was determined by the extent of the surface, the seat of the chemical action. The original cell of Planté was made of practical utility by Faure, who improved the amount of chemical energy to be transformed into electrical power by coating the surface of the plates with lead peroxide and by enlarging the surface by mechanical devices. Improvements on the methods of Faure have been made by Brush and many others, so that now a storage cell or an accumulator can be so charged by a battery or dynamo as to give out an amount of electro-motive force only limited by the chemical action occurring at the surface of the plates. Such an accumulator will furnish sufficient power for lighting, heating, or mechanical work.

The storage cell is now employed to furnish light for illuminating the eye, the ear, the throat, and other cavities for cautery purposes in all the varied operations in which the electric knife is used, and, with suitable controllers and rheostats, for the numerous applications of galvanism in medical practice. By means of a storage cell, therefore, the electrical work of an office, including faradic, galvanic, illuminating, and caustic, can be carried on without the agency of the ordinary batteries. When a storage cell is exhausted or has run down, it can be recharged again at the central office, or it can be recharged from the street main by suitable adapter and controller.