BATTERY CHARGINGN Chester Simpson National Semiconductor BATTERY CHARGING Introduction The circuitry to recharge the batteries in a portable product is an important part of any power supply design. The complexity (and cost) of the charging system is primarily dependent on the type of battery and the recharge time. This chapter will present charging methods, end-of-charge-detection techniques, and charger circuits for use with Nickel-Cadmium (Ni-Cd), Nickel Metal-Hydride (Ni-MH), and Lithium-Ion (Li-Ion) batteries. Because the Ni-Cd and Ni-MH cells are similar in their charging characteristics, they will be presented in a combined format, and the Li-Ion information will follow. NI-CD/NI-MH CHARGING INFORMATION In the realm of battery charging, charging methods are usually separated into two general cat……