A systematic approach for determining the optimal battery preheating cut-off temperature for electric vehicles operating in cold climates

Range anxiety in cold climates, stemming from batteries' diminished performance at low temperatures, poses a significant barrier to the widespread adoption of electric vehicles (EVs). Battery preheating is regarded as an effective solution to address this issue. However, determining a reasonable preheating cut-off temperature is challenging due to the need to balance heating energy consumption and battery performance recovery across various environments, battery states, and vehicle power demands. This study investigates the effect of preheating cut-off temperature on battery available energy and introduces a systematic approach for determining the optimal battery preheating cut-off temperature. It also proposes a heating strategy aimed at maximizing battery energy and meeting the cold-start power needs of EVs. The results indicate that, regardless of the heating system used, the proposed strategy significantly improves EVs' driving range in low temperatures. Specifically, under the same driving conditions, implementing the proposed strategy can increase the driving range retention rate from 68.6 % to 79.5 % at −20 °C. This framework can facilitate the rapid development of optimal heating strategies for different EV battery preheating systems.