This paper uses a buck ZCS PWM converter in battery chargers. Figure 1 displays the basic configuration of the developed charger circuit, including (1) a dc source, (2) a PWM control circuit to control the switching of switches in the buck converter, and (3) a buck ZCS resonant converter. In addition to having safe operation and small-sized circuit volume, the developed novel charger has a very high efficiency, and controls the resonance time without restraint at a constant frequency.