The Timing of Mid-trip Electric Vehicle Charging

This study aims to explore how factors related to the charging infrastructure, battery technology and usage characteristics affect the way people currently charge their electric vehicles, as well as to explore whether good use of battery capacity can be encouraged. Using a stochastic frontier model applied to panel data obtained in a survey on electric vehicle usage in Japan, the remaining charge when mid-trip fast charging begins is treated as a dependent variable. This variable is significantly affected by user anxiety about charging opportunities, which differs by user and business type. The estimation results obtained using four models, for commercial and private vehicles, respectively, on working and non-working days, show that there are great opportunities to encourage more efficient charging behavior by alleviating anxiety. It appears that the stochastic frontier modeling method is an effective way to model the minimum charge at which fast-charging should be initiated, since it incorporates user characteristics into the estimation process to some extent.