Lead-acid batteries, invented
in 1859 by French physicist Gaston Planté, are the oldest type of galvanic cell battery. Despite having the second lowest
energy-to-weight ratio (next to the nickel-iron battery) and a correspondingly low energy-to-volume ratio, their ability to
supply high surge currents makes the cells perfect to maintain a relatively large power-to-weight ratio. This, in addition
with their low cost, makes them ideal for use in cars, as they best provide the high current required by automobile starter
motors. They are also used in vehicles such as forklifts, in which the low energy-to-weight ratio may in fact can be considered
beneficial since the battery can be used as a counterweight.
Interestingly enough, according to a site done by the battery council international, lead
acid batteries are the most recycled product in america. They are the most commonly used, manufactured, and purchased battery
on the market today. Lead acid batteries, though not as exciting as some of their battery counter-parts, are the most relied
on battery to date.
car batteries for a '12 volt' system consist of six cells of 2.1 V nominal voltage. Each cell contains (in the charged state)
electrodes of lead metal (Pb) and lead (IV) oxide (PbO2) in an electrolyte of about 37% (or 6-12M) w/w sulfuric acid (H2SO4).
In the discharged state both electrodes turn into lead(II) sulfate (PbSO4) and the electrolyte loses its dissolved sulfuric
acid and becomes primarily water. Due to the freezing-point depression of water, as the battery discharges and the concentration
of sulfuric acid deceases, the electrolyte (including the more modern gellified electrolyte of the gel battery) is more likely
to freeze .
sell chemical additives (solid compounds as well as liquid solutions) that supposedly reduce sulfate build up and improve
battery condition when added to the electrolyte of a vented lead-acid battery. Such treatments are rarely, if ever, effective.”-http://www.answers.com/topic/lead-acid-battery-1