The flourishing development and the increasing interest in renewable energy sources need to look for new approaches to convert and distribute power in a highly efficient way. In line with this objective, this work presents the analysis, design, and PCB implementation of a novel topology of resonant low-voltage battery charger fed by a 48-cell photovoltaic (PV) module. The work aims to go beyond the existing research about PV-fed low-voltage battery chargers, by proposing a new solution from both the topological and control points of view. The DC-DC power converter designed in this work consists in a single-stage, frequency-modulated battery charger that exploits both topological and control-based solutions to achieve Zero-Voltage Switching (ZVS) and Zero-Current Switching (ZCS) of the converter MOSFETs.