Six things you didn’t know about car batteries
Johannesburg - As today’s cars become increasingly dependent on their electronics, so the source of their electrical power becomes more important. Not only does the battery run the car, it also powers the alarm, the central locking system, and all the driver aids.
Everybody knows that a conventional car battery is a plastic case containing thin lead plates suspended in dilute sulphuric acid. But the history of ‘electricity in a box’ predates both the name and the automobile.
Here, thanks to First National Batteries, are six things you never knew about the history of car batteries:
Italian physicist Alessandro Volta created the first documented battery in 1799 by stacking layers of zinc, silver and porous wood or fabric soaked in acid on top of each other. It wasn’t the first device to generate electricity, but it was the first to emit a steady current.
However, some scientist think a clay jar discovered in Iraq in 1938 is the earliest battery. Believed to be 2000 years old, it contains an iron rod surrounded by a copper cylinder - and if you fill it up with acetic acid (vinegar) it can produce up to two volts, just like one cell of a modern battery. What its original purpose was, however, is unknown so that’s just a theory.
Battery is a relatively recent term. Volta’s ‘power stack’ was called a Voltaic Pile (to this day the French word for a battery is ‘pile’, pronounced ‘peel’) and the unit of electromotive measurement was named the volt in his honour. Okay, it didn’t look anything like a modern battery, but the top and bottom plates acted as positive and negative terminals in the same way modern batteries do.
The rechargeable lead acid battery was developed in 1859 by French inventor Gaston Planté. It had a thick glass case (at the time glass was the only readily available material that was immune to sulphuric acid) and the earliest ones were open on top like a fish-tank which, as a lead-acid battery produces highly flammable hydrogen gas while charging, made them something of a fire risk.
Electrical engineers called them accumulators, and used them to power the earliest radio transmissions. We owe Planté a vote of thanks - without his invention, we wouldn’t be able to run our mobile devices, laptops, TV remotes, or start our cars at the turn of a key.
But it was chemical engineer Camille Alphonse Faure who in 1881 invented lead sulphate plates, lined them up like the guns in a siege battery, connected them in series to produce first six and later 12 volts, and sealed the top of the case with tar to make them usable in early electric cars - notably the ‘Jamais Contente’ (Never Satisfied) in which red-bearded Belgian speed freak Camille Jenatzy became the first person to travel at more than 100km/h on 29 April 1899.
Faure’s batteries also made possible electric starting of combustion engines. This became an issue as engines became more powerful and cranking them by hand more dangerous. In fact the first production starter motor in the United States was developed by Henry M Leland and Charles Kettering for the 1912 Cadillac after an engineer at the company was killed when a car’s crankhandle kicked back and hit him on the head.
Many different chemical reactions are used today to generate electric power, notably nickel/cadmium, nickel metal hydride and lithium/iron phosphate. But lead and sulphuric acid are still the most widely used in automotive applications - so the next time you press the button on the remote and your car’s indicators greet you, say a quiet thank-you to Volta, Planté and Faure, who made effortless electric starting possible.