This paper summarizes the application of system safety engineering methods to the evaluation, management and mitigation of some potential safety risks of high voltage automotive battery systems. The battery system in electric vehicles is very complex and must balance many attributes such as performance, cost and timing while not compromising safety criteria. Among other things, a thorough and methodical approach to battery safety is necessary to achieve this balance. System safety engineering methodology provides such an approach and can be applied as a useful framework.
Potentially hazardous conditions related to functional safety (for example, charge control) as well as primary safety (for example, chemical and mechanical hazards) may both be addressed by applying such a system safety engineering methodology. Hazard identification and assessment, safety requirements development and definition, application of various safety analysis methods, and verification / validation activities are all part of this approach. Typical battery abuse testing, as well as newly defined limit testing, supports the effort.
Documentation, traceability and reviews provide a method to verify that all issues are addressed as well as providing a method to retain information for future reference. A description of the process and specific examples of its application are provided so that both new and experienced system safety practitioners can gain insights to the application of the system safety process to systems which include both functional and primary safety hazards.
