Battery Electric Transit Bus Safety and Performance Testing: A Review of Current Practices and Correlation to Battery Failure Modes

Transit agencies around the world have been investing in more battery electric buses (BEB) in an effort to combat the growing negative externalities stemming from the use of petrochemicals in combustion transit vehicles. These buses use new propulsion systems based primarily on lithium-ion batteries to cut carbon pollution and promote cleaner, faster, and safer rides. As new electrification technologies continue to penetrate the bus transit market, there is a continuous need to evaluate the safety and performance of these battery electric systems. To meet the safety and performance needs of technologies in transit buses, regulations and standards have been established to define best testing and industry practices.

This paper details the current state of battery standards and regulations in automotive and transit vehicles, with consideration of battery failure modes and effects. Various governments and standard organizations have established numerous different regulations and standards. This paper presents a generalization of established safety and performance testing practices used for BEB. The battery tests presented are independent of specific standards or regulations and represent the majority of battery tests that are required or recommended for BEBs. These safety tests are tied back to the failure modes and effects that these tests are intended to cover. Furthermore, this paper presents a summary of the current gaps in BEB safety and performance testing.