Thermal Runaway Explains Why Waymo Cars Burned So Completely in the Recent Los Angeles Protests
During the recent protests in Los Angeles, a shocking incident occurred when fires triggered “thermal runaway” in several Waymo robotaxis’ lithium-ion battery packs. This phenomenon led to temperatures exceeding 1,000 degrees Celsius, resulting in the vaporization of much of the cars and the release of lung-searing hydrogen fluoride.
Imagine witnessing a car engulfed in flames until it seemingly vanishes, leaving only remnants of wheel rims and traces of aluminum. This surreal sight unfolded in Los Angeles, where protesters set ablaze at least five Waymo-branded Jaguar I-Pace robotaxis. The intensity of the fires led to the near-total destruction of the vehicles, with the shell of each car disintegrating, leaving only the framework behind.
The devastating impact of the fires can be traced back to the lithium-ion battery packs used in the I-Pace vehicles. These batteries can store approximately 90 kilowatt-hours of energy, equivalent to about 170 pounds of TNT. When exposed to external factors such as punctures, overheating, or incendiary devices, these batteries can undergo a dangerous chain reaction known as “thermal runaway.” This process results in the generation of extreme heat, causing the battery cells to ignite and release energy uncontrollably.
As the battery burns, temperatures can soar past 1,000 degrees Celsius, turning the pack into a virtual furnace. The high temperatures cause various components of the car to melt and disintegrate rapidly. The aluminum sections of the car’s floor liquefy, while magnesium parts flare up, emitting intense white light. Plastics vaporize, wheels lose their tires, and even the lidar mast on the roof deforms under the extreme heat. The location of the battery on the floor, known as “skateboard architecture,” contributes to the upward and outward spread of flames, engulfing everything in their path.
One of the most concerning aspects of these fires is the release of hydrogen fluoride, a toxic and lung-searing gas produced by burning lithium-ion batteries. Exposure to this gas can lead to severe respiratory issues, with symptoms such as throat burns and breathing difficulties. The high levels of hydrogen fluoride emitted during these fires pose a significant health risk to both bystanders and first responders.
Firefighters often refer to such incidents as “battery box fires,” which present unique challenges in terms of extinguishing the flames. Traditional flame-retardant methods are often ineffective, necessitating the use of high-pressure water lances or immersion pits to cool the batteries and prevent reignition. The sheer amount of water required to extinguish a burning lithium-ion battery highlights the complex and hazardous nature of these fires.
While car manufacturers have implemented safety measures to prevent thermal runaway, incidents like the recent Waymo fires underscore the inherent risks associated with lithium-ion batteries. Despite advancements in battery technology and vehicle design, the potential for catastrophic fires remains a critical concern for electric vehicles.
In conclusion, the events that transpired during the Los Angeles protests serve as a stark reminder of the challenges posed by lithium-ion battery fires. While electric vehicles offer numerous environmental benefits, the risks associated with thermal runaway and battery fires highlight the importance of ongoing research and safety precautions in the development of electric vehicles.
