In 1802, Dr. William Cruickshank designed the first electric battery capable of mass production. Cruickshank had arranged square sheets of copper, which he soldered at their ends, together with sheets of zinc of equal size. These sheets were placed into a long rectangular wooden box that was sealed with cement. Grooves in the box held the metal plates in position. The box was then filled with an electrolyte of brine, or watered down acid.

Figure 4: Cruickshank and the first flooded battery.
William Cruickshank, an English chemist, built a battery of electric cells by joining zinc and copper plates in a wooden box filled with electrolyte. This flooded design had the advantage of not drying out with use and provided more energy than Volta’s disc arrangement. © Cadex Electronics Inc.

The third method of generating electricity was discovered relatively late — electricity through magnetism. In 1820, André-Marie Ampère (1775-1836) had noticed that wires carrying an electric current were at times attracted to one another, while at other times they were repelled.

In 1831, Michael Faraday (1791-1867) demonstrated how a copper disc was able to provide a constant flow of electricity when revolved in a strong magnetic field. Faraday, assisting Davy and his research team, succeeded in generating an endless electrical force as long as the movement between a coil and magnet continued. The electric generator was invented. This process was then reversed and the electric motor was discovered. Shortly thereafter, transformers were developed that could convert electricity to a desired voltage. In 1833, Faraday established the foundation of electrochemistry with Faraday's Law, which describes the amount of reduction that occurs in an electrolytic cell.

In 1836, John F. Daniell, an English chemist, continued with the research of the electro-chemical battery and developed an improved cell that produced a steadier current than Volta's device. Until then, all batteries had been composed of primary cells, meaning that they could not be recharged. In 1859, the French physician Gaston Platé invented the first rechargeable battery. This secondary battery was based on lead acid chemistry, a system that is still used today.