Plug-in hybrid electric vehicles (PHEVs) have a conventional internal combustion (IC) engine running on fossil fuels as well as an electric motor that gets supply from a battery which can be charged using external supply like electric vehicles (EVs). Using renewable energy sources like fuel cells or solar photovoltaics (PVs) for charging the battery, EVs and PHEVs can become even cleaner as far as the environment is concerned. These energy sources generate a low voltage which is limited to around 40-50 V due to practical constraints, while batteries that power EVs and PHEVs need a charging voltage of around 350 V. This paper presents a novel naturally clamped, isolated, DC-DC converter which has a voltage doubler rectifier at the output end which converts 12 V supply from renewable sources to 350 V to enable battery charging. © Springer Nature Singapore Pte Ltd. 2018.