How do you design a functionally safe battery management system?

Functional safety design for BMS follows ISO 26262: ASIL D for critical functions like contactor control and overcurrent protection, ASIL B for SOC/SOH estimation affecting range. Architecture includes: Redundant voltage and temperature sensing, independent hardware monitoring IC watching microcontroller, safe state definition (disconnect battery), fault detection within required diagnostic coverage, and certified safety microcontrollers. Software uses defensive programming, plausibility checks, and watchdog supervision. Safety concept addresses single points of failure with redundancy or detection. Validation includes fault injection testing and FMEA-based test coverage.