Abstract: Electronic equipment is increasingly becoming smaller, lighter, and more functional, thanks to the push of technological
advancements and the pull from customer demand.

        The result of these demands has been rapid advances in battery technology and
in the associated circuitry for battery charging and protection.
For many years, nickel-cadmium (NiCd) batteries have been the standard for small electronic systems. A few larger systems, such
as laptop computers and high-power radios, operated on "gel-cell" lead-acid batteries. Eventually, the combined effects of
environmental problems and increased demand on the batteries led to the development of new battery technologies: nickel-metal
hydride (NiMH), rechargeable alkaline, lithium ion (Li+), and lithium polymer battery charger. These new battery technologies require more
sophisticated charging and protection circuitry to maximize performance and ensure safety.