The Electric battery was primarily developed by Alessandro Volta in the year 1800. He put a layer of cardboard between zinc and copper which produced electricity when mixed with salt water. The reason he developed it was to prove that a combination of metal and an electrolyte produces an electrical current. Volta's battery was the first known Wet-cell battery. Later on through the 1800's, Volta's discovery sparked an interest in personal electricity storage. In 1896, the first publically available battery was the Carbon-Zinc battery used to power doorbells and telegraphs. The Carbon-Zinc battery is composed of a carbon rod, a zinc container, ammonium chloride, manganese dioxide, zinc chloride and carbon powder. This dry cell, Carbon-Zinc battery is still used today as a cheap, affordable battery. The shelf-life of the present day Carbon-Zinc batteries are about 1.5 years.