Electrics & Electronics: Electrical Principles: Batteries
Lead acid batteries
 
Lead-acid batteries are the most commonly used rechargeable batteries today. They also represent the oldest design with one of the worst energy-to-wight ratios, they are cheap and can supply the high surge currents needed in started motors.
 
Batteries & cells
 
Increasing the surface area of the plates in a cell increases its current capacity, but not its nominal voltage. Cells connected in series make a battery. The number of cells determines its nominal voltage.
 
Battery charging
 
During discharge, the chemical energy of the plates is transformed into electrical energy, then used to perform work. The plates develop the same composition, which reduces the potential of the cell.