Architectural Pathways and Integration Constraints for Feasible Onboard Electrochemical Impedance Spectroscopy for Battery Electric Vehicles

Reliable battery health assessment is essential to accelerate battery electric vehicle (BEV) adoption, yet most existing in-vehicle methods do not capture the complex processes driving ageing. Electrochemical impedance spectroscopy (EIS) offers deeper diagnostic insight but faces significant architectural and integration constraints. This study establishes a rigorous system-level framework for practicable onboard EIS implementation, focusing on the integration within Battery Management System (BMS) and powertrain architectures. Various integration topologies for cell-, module- and pack-level EIS are evaluated, highlighting their key trade-offs. The viability of the presented architectures is assessed through an application-specific Multi-Criteria Decision Analysis (MCDA) for mass-market, high-performance and circular economy use-cases. This study confirms the feasibility of onboard EIS while providing industry and scientific stakeholders with practical guidance to advance battery diagnostics for next-generation BEVs.