In this study, a novel high efficiency DC/DC boost converter is proposed to use in PV systems. The converter includes only one metal oxide semiconductor field effect transistor (MOSFET) switch, and two diodes. It is shown theoretically and experimentally that the only switch of the converter is turned on and turned off respectively under zero current switching (ZCS) and zero voltage switching (ZVS) conditions, and the two diodes are turned on/off under ZCS condition, so there are no switching losses. To evaluate the performance of the DC/DC boost converter, a novel photovoltaic (PV) based battery charger consisting of the proposed converter and other units is also implemented. A prototype of the proposed PV battery charger has been built, and experimental results are presented that explicitly validate theoretical results. It is experimentally verified that the contribution of this work is to present a novel high efficiency DC/DC boost converter having the highest efficiency (98.21%) compared to the other DC/DC boost converter topologies reported in the literature.