Optimal Battery Sizing for Urban Electric Vehicles: Balancing Purchase Cost and Charging Inconvenience

Nowadays electric vehicles (EVs) are playing a pivotal role to support sustainable mobility and achieve desired levels of emission reduction. Optimal size of their batteries is still a topic of research, as there exists a trade-off between extended range and increasing cost and weight. In this paper, we introduce a quantitative framework to evaluate optimal electric vehicle (EV) battery capacities, considering two criteria: upfront vehicle cost and charging inconvenience cost. For this purpose, we (1) develop a comprehensive model for charging inconvenience costs, incorporating both charging time and detours, improving on existing studies, (2) show, through simulation and analytical models in abstract as well as realistic (Paris) scenarios, how charging inconvenience cost is affected by different battery capacity and charging infrastructure configurations, (3) introduce an optimisation framework to determine optimal battery capacities based on charging inconvenience and vehicle cost, and (4) show that optimal battery capacities can be influenced by strategic investments in charging infrastructure and tax/incentive policies. The proposed framework can be used to identify optimal battery capacities in a given charging environment, but also to estimate the convenience benefits of charging infrastructure investments, providing a nuanced framework for optimizing the design of cost-effective, convenient and sustainable EV systems.