Investigation on the thermal performance of a battery thermal management system using heat pipe under different ambient temperatures

The thermal performance of a battery thermal management system (BTMS) can be enhanced by cooling strategies, which are seldom taken into account in the study of heat pipe-based BTMS (HP-BTMS). The effects of coolant flow rate, ambient temperature, coolant temperature and start-up time on the thermal performance of HP-BTMS are crucial for the development of cooling strategies and are experimentally investigated in the present study. Results show that the thermal performance of HP-BTMS increases slightly with the decrease of ambient temperature as it is under 25 °C. When the ambient temperature is under 35 °C, the thermal performance of HP-BTMS can be kept nearly unchanged by reducing coolant temperature. The enhancement is little when ambient temperature is under 25 °C. Additionally, a drastic rise in the non-uniformity of battery temperature is observed at the moment of HP-BTMS initiation if HP-BTMS starts operating after battery temperature exceeds equilibrium value. Finally, intermittent cooling and constant cooling can achieve similar battery cooling performance, which indicates that the power consumption can be reduced by decreasing running time of HP-BTMS.