Compliance of ISO 26262 safety standard for lithium ion battery and its battery management system in hybrid electric vehicle

Abstract

This paper is an application of ISO 26262 functional safety standards for the proper design, development and validation of Lithium ion battery system. Lithium ion battery plays very important role in Electrification of the vehicle. It has capability of high discharge currents and better energy density compared to more traditional NiMH batteries. With these capabilities, batteries have safety hazards like high risk of fire, explosion, heat, smoke. Battery management system (electronic unit) can reduce the risk by controlling the intrinsic parameters or functionality of battery to avoid safety hazards. There are several standards typically considered for safety and construction of battery pack, but it do not address the risk of electronic malfunction of the battery controller or vehicle system. ISO 26262 process and concept can be applied to bridge this gap and ensure the system safety of plug-in vehicles equipped with large-scale battery packs. In this paper, lithium ion battery system integration and validation aspects are covered to achieve functional safety. It also covers key components of ISO 26262, and qualification of hardware and software of batteries. It covers fail safe methodologies for design of battery system for electric and hybrid vehicles and validation of Lithium ion battery system.