Battery Pack Sizing Method - Case Study of an Electric Motorcycle

Abstract

This paper presents a method for battery pack sizing for electric vehicles, applied to the case of an electric motorcycle. A novel way of analyzing battery pack performances in a single graphical tool is proposed. It is intended to help engineers get a broader understanding of the influence of design decisions from the early stages of the engineering process. In multi-cell battery packs, specifications such as energy, power, volume and mass are proportional to the total number of cells, while voltage, current are dependent of the series and parallel arrangement. Thus, presenting results as functions of the number of cells in series and parallel allows to compare quickly the various performance metrics of a pack. By applying the design constraints of the technical requirements as limiting functions, one can easily select a suitable solution that meets design goals, or assess the effect of design constraints. This graphical design tool could be used to size other electric energy storage devices such as lithium-capacitors, super-capacitors or battery pack of other chemistries than lithium- ion.