An Optimal Battery Sizing Co-Design Approach for Electric Racing Cars

The electrification trend in automotive industry is having a huge impact also in racing contexts. Indeed, Formula E, the most important competition for electric vehicles (EVs), is currently evolving to its third generation, developing more powerful cars. With respect to fuel-based vehicles, batteries represent the main shortcoming in EVs, due to lower energy and power densities compared to fuel tanks. For this reason, battery sizing in EVs is a real challenge, especially in racing applications, where its size significantly affects vehicle performance. In this letter, the battery sizing for electric racing cars is formulated as a co-design problem, tackled through a double-layer nested optimization approach. The external layer optimizes the battery pack design parameters and the internal one computes its optimal use, mainly the battery power request, to achieve the minimum race time. Finally, the proposed approach is applied to a meaningful case study, that is the Formula E battery pack sizing for the 2021 Rome and Valencia ePrix.