The origins of the battery date back as far as 250BC with a device named the ‘Bagdad Battery’. In 1938, a German archaeologist Wilhelm K nig reportedly excavated a 130 mm long clay jar in Khujut Rabu near Baghdad, Iraq. The jar contained a copper cylinder, in turn covering and protecting an iron rod, isolated from the copper by asphalt. The practical use of the device is uncertain due to the belief that ancient civilisations did not have electrical power and therefore would not have a device which operated on electrical principles. Some researchers believe that it was used to electroplate metallic items however all these beliefs are not 100% certain and are still disputed today.

The Bagdad Battery

What is know, is that in 1780, Luigi Galvani discovered that when two different metals (copper and zinc for example) were connected together and then both touched to different parts of a nerve of a frog leg at the same time, they made the leg contract. He called this “animal electricity”. This discovery paved the way for all electrical batteries.

The first ever battery was demonstrated by Count Alessandro Volta an Italian physicist who in 1800 found from experiments that different metals in contact with each other created electricity.

He therefore built a stack of alternating discs of zinc, blotting paper soaked in saltwater, and silver (or copper, depending on who you believe). When he attached a wire to the top and bottom discs he measured a voltage and a current. He found that the pile could be stacked as high as he liked, and that each additional layer increased the voltage by a fixed amount, depending on the metals he used. The current is produced because of a chemical reaction arising from the different electron-attracting capabilities of the two metals. This device became known as a 'voltaic pile' (the French word for 'battery' is 'pile').

An example of Count Alessandro Volta's Voltaic pile