Gaston Planté invented the first Lead-acid battery in 1859, making it the oldest type of rechargable battery. Nearly 3 million tons of lead were used in the manufacture of batteries in 1992. Most of the world’s lead–acid batteries are automobile starting, lighting and ignition (SLI) batteries. An estimated 320 million units shipped in 1999. Sealed lead acid (SLA) batteries have a low energy-to-volume ratio as well as a low energy-to-mass ratio. They are able to supply high surge currents, which means that the cells maintain a relatively large power-to-weight ratio. These features, as well as the fact that they are inexpensive, makes them an excellent choice for use in motor vehicles. Sealed lead acid batteries store energy in a chemical form that can be released on demand as electricity. (continue reading…)