Lithium-Ion Battery Transit Bus Fire Prevention and Risk Management

The risk of lithium-ion battery fires is a concern for transit agencies that are considering whether to electrify their bus fleets. The transit industry has largely addressed lithium-ion battery fire risk by incorporating rigorous early detection and protection protocols in battery management systems that prevent thermal runaway when the battery pack is physically compromised through improper use or external impact. At current zero-emission bus (ZEB) fleet scales, the magnitude of these risks is relatively small; there is, however, no widespread understanding of how lithium-ion battery fire risks will be magnified when fleet size increases. Damaged cells in a lithium-ion battery can lead to thermal runaway, a phenomenon in which a failure in the architecture of a battery cell (e.g., a short) causes the heat of the battery to rapidly increase, releasing flammable gas which then ignites, triggering similar events in adjacent cells. The ensuing fires are difficult to extinguish and must be addressed with significant quantities of specialized fire suppressants. There are also documented instances of stranded energy remaining after a lithium-ion battery fire is extinguished, causing batteries to reignite after the fires have been initially suppressed by first responders. The objective of this research is to develop a guide to lithium-ion battery transit bus fire prevention and risk management with recommended practices for original equipment manufacturers, battery companies, transit agency facilities, and vehicle maintenance. The focus should be on zero-emission transit bus fire prevention and risk management. A parallel project is addressing power generation, distribution, and charging infrastructure; institutional relations; and operations. At a minimum, the research team shall (1) review the potential root causes of ZEB lithium-ion battery fires, including an analysis of the potential of such fires to spread to other vehicles or reignite after suppression; (2) evaluate risk mitigation options; (3) identify, evaluate, and summarize effective practices for fire risk mitigation and suppression, focusing on agencies that store and charge their buses in indoor facilities; (4) identify quantitative and qualitative metrics that can be used to evaluate vehicle and battery performance as they relate to fire and life safety; and (5) address the technical, economic, and institutional barriers to implementing identified solutions.

• Record URL:
  http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=5258
• Supplemental Notes:
  • Contract to a Performing Organization has not yet been awarded.

Language

• English

Project

• Status: Proposed
• Funding: $350000
• Contract Numbers:

  Project E-14

• Sponsor Organizations:

  Transit Cooperative Research Program

  Transportation Research Board
  500 Fifth Street, NW
  Washington, DC    20001

  Federal Transit Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Project Managers:

  Parker, Stephan

• Start Date: 20230221
• Expected Completion Date: 0
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Electric buses; Fire prevention; Lithium batteries; Risk management; Transit safety; Vehicle fires
• Subject Areas: Energy; Public Transportation; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 01789266
• Record Type: Research project
• Source Agency: Transportation Research Board
• Contract Numbers: Project E-14
• Files: TRB, RIP
• Created Date: Nov 22 2021 10:05PM