and battery backup of computer memories. Several types of lithium cells are
available, with voltages from of 2 V to 3.5 V and current ratings from the
microampere to the ampere range.
Nickel-Cadmium
Commonly called “Ni-Cads,” these are the most popular, general-purpose
rechargeable batteries available. They have long service lives, operate over
wide temperature ranges, and are manufactured in many styles and sizes,
including C, D, AAA, and AA. Inexpensive chargers make it economically
feasible to use nickel-cadmium batteries for home entertainment equipment.
Lead-Acid
This is the familiar automotive battery. Its basic cell voltage is about 2
volts, but typically, six cells are connected internally to provide 12 volts at
its terminals. Lead-acid batteries are capable of delivering large current (in
excess of 100 A) for short periods as required, for example, to start an
automobile.