In November of 2023, the WPI Fire Protection Engineering Department in collaboration with the Boston Fire Department and UL’s Fire Safety Research Institute performed and analyzed a full-scale battery electric vehicle (BEV) fire test. This work was advised by Professor Milosh Puchovsky, supported by WPI fire laboratory staff Frederick Brokaw and Mahesh Kottalgi, and conducted by fire protection engineering PhD students Weixuan Gong, Jorge Valdivia, and Jon Zimak. An overview of the testing was presented at the 2024 National Fire Protection Association Conference and Expo in Orlando Florida. The slides are provided here for reference.
The experiment involved the instrumentation, ignition, initiation of thermal runaway, and subsequent suppression of a 2020 BEV. The primary goal of this work is to test and evaluate the response of an electric vehicle to external ignition sources in outdoor windy conditions. The primary objectives of the test are to gather data on fire development, observe firefighter interactions during suppression efforts, and make recommendations for subsequent BEV testing. This initiative aligns with the overarching objective of enhancing our comprehension of BEV fire behavior, encompassing the exploration of products of combustion and refining fire suppression practices.
The test was conducted outdoors with a fully charged accident-free vehicle and was ignited by a gas burner. Instrumentation included thermocouples on and within the vehicle, flow meters, and heat flux gauges. Video and thermal imaging cameras were placed within and around the vehicle.
It took 40 minutes for the vehicle to ignite with the burner heat release rate gradually increasing from 20 kW to 100 kW. The test results can be divided into 5 regimes: vehicle ignition, an initial suppression, a post-initial suppression “battery fire”, a second much longer suppression period, and a final phase of test conclusion. The two distinct fire periods between suppression resulted in marked differences in fire behavior, incident heat fluxes, and water flow measurements. The first event resulted from the concurrent combustion of the vehicle's flammable materials and the thermal runaway of the battery pack. The subsequent event, referred to as the "battery fire", involved a jet-like flame emanating from the battery pack, while the remaining flammable materials of the vehicle were nearly consumed. A comprehensive discussion on the instrumentation plan, test methodology, and data collected is provided in the slides along with an analysis of the test results and insights to support future testing endeavors.
