The performance attributes of a heterogeneous multi-battery pack system significantly impact the electric vehicle's performance. This study aims to investigate the power reduction and energy utilization phenomena in heterogeneous battery pack configurations that arise due to an uneven current split, focusing on defining the power ability curves and usable energy for the mixed system. A Multiphysics-based system model has been developed to investigate the factors contributing to power loss and usable energy when the aged packs are mixed with fresh packs. Different methods, viz., scaled, aged, and interpolation, are proposed to estimate the power retention curves for one and two fresh packs mixing into the homogeneous system. Also, energy evaluation helps in identifying the impact on vehicle range, which is an important attribute of vehicle performance. Altogether, having power ability curves and usable battery energy (UBE) for a heterogeneous multi-pack system helps in defining the decision-making strategies for the refurbishment of ESS during replacement and maintenance activities in EVs. Some strategies are introduced at the end using aged and scaled methods to conduct the most conservative power estimations while pack mixing. Energy evaluation is performed at the ESS level, highlighting the impact of fresh pack on the aged system usable energy.
Rathore et al. (Tue,) studied this question.