ABSTRACT Low carbon vehicle developments are an area of intense activity for automotive manufacturers. Pure Electric Vehicles (EVs) specifically are becoming viable in part due to advances in attainable battery energy density, realising useable vehicle performance. There are many new challenges for effective thermal management in order to achieve a design where safety, performance, reliability and life are accomplished at reasonable cost. This paper discusses an EV thermal system development from early design through to an integrated cooling and heating solution. It proposes a dual mode cooling system to satisfy both powertrain and battery thermal management, considering vehicle performance and range.