Last month SAE International, in collaboration with China Automotive Technology Research Center (CATARC), held the first meeting of the new Bus Battery Systems Committee.  The formation of the committee and the undertaking of its work, was recommended by NAATBatt International in response to growing concerns about the safety of large format lithium-ion batteries increasingly installed in mass transit buses around the world.

As I noted in an earlier column, China, the leading market for electric buses, has already started to implement safety regulations for its electric buses, most notably by banning the use of “tri-metal” (e.g., NMC) chemistries in bus batteries.   By contrast, there are no regulations or standards for electric bus batteries in the United States.  The need to establish some sort of standards in this area, so that the safety of the commuting public is adequately protected from batteries which, if misused, could pose a serious hazard, is self-evident.

The new Bus Battery Systems Committee will be chaired by Lu (Lucas) Chun of CATARC.  NAATBatt International will be represented on the committee by our President, Bob Galyen, Dave Roberts of the Battery Innovation Center, and John Warner of Enerdel.  NAATBatt joins the American Public Transit Association and the Canadian Urban Transit Research and Innovation Forum as one of the major trade associations supporting the work of the committee.

At its initial meeting, the committee adopted the following mission statement:

“Create a series of system level standards which provide for integration and guidance of energy storage system for all sizes of electrified buses.  This includes integration into Plug in Hybrid Electric Vehicle, Hybrid Electric Vehicle and Battery Electric Vehicle application types with size classification of small, mid-size, large, extra-large and city size buses.  These documents intentionally do not include the cell, module and pack level standards which are already addressed in other international standard organizations.”

The initial goal of the committee is to create a master document entitled review “Integration of Battery Pack Systems in Bus Electrification”.  It is intended that that document will become the parent document for “subsystem or children” documents dealing with various aspects of bus battery safety.  Those subtopics will likely include topics such as crashworthiness, shock hazard, venting, flame/heat/explosion, rescue/escape, first and second response, operating parameters, subsystem integration and general vocabulary.

The issue of electric bus safety is of major importance, and one that has to some extent been underappreciated to date.  The size of bus batteries, combined with their proximity to large numbers of the general public, combined with the complete lack of any regulatory standards for such systems should identify this as an area of high risk and, as important, of high potential negative visibility.  A major tragedy involving an electric bus will have serious consequences for all companies working with large format lithium-ion batteries, whether those companies are working on bus systems, light vehicles, stationary energy storage or any other large format applications.

NAATBatt members wishing to become involved in the work starting up on bus battery safety should contact Bob Galyen or myself.  Whether your business is directly involved in mass transit buses or not, all NAATBatt members need to keep a close eye on this issue.