Why Waymo cars fire in recent Los Angeles protests

The thermal runaway explains why Waymo cars were completely burned in the recent Los Angeles protest

Denni Ellis Bechado Edited by Dean Visser

Imagine watching the car evaporate and the street itself burn until it’s drooping. It happened in Los Angeles on Sunday, with protesters torching at least five Waymo brand Jaguar I-Pace Robotaxis. Once the smoke was cleared, the entire shells of each car, including the roof, doors, hood, trunks, and body panels, had disappeared.

Why did the fire cause such an erasure? The answer starts with the battery. Each I-Pace can carry around 90 kilowatt-hours of stored chemical energy, comparable to about 170 pounds (77 kilograms) of TNT. Its energy is distributed in hundreds of lithium-ion pouch cells sealed with a flammable electrolyte and separated by thin polymer membranes, like snack bag plastic. If a single cell is punctured or overheated, or is burning in a calcined Cen device, the chemical reaction generates more heat than the cells shed, and adjacent cells follow a chain reaction. This positive feedback loop is called “thermal runaway.” According to 2024 study of Journal of Power Sources, As the battery burns, its temperature can soar above 1,000 degrees Celsius.

At that point, the pack will become its own furnace. The aluminum section of the car floor yields, liquefied to about 660 degrees of liquefaction, bringing the underbody. Magnesium parts – seat base frame, bracket holding steering column, cross car beam behind the dashboard – fold bright white. Magnesium patches can be caught on fire and burned violently. The plastic disappears as steam, the wheels lose tires, and even the rider mast on the roof resembles a marshmallow that was quickly heated. Research in 2025 Fire Technology And a 2023 Research Applied energy Note that placing batteries on a floor, which may be called “skateboard architecture,” makes the floor the hottest zone. Therefore, the flame is radiated upwards and outwards, cooking all of the above.

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Meanwhile, battery cells expel hydrogen fluoride, a toxic lung ear gas recorded in laboratory testing combustion of commercial lithium packs. Among the ominous scenes from the recent Los Angeles protests surrounding the federal immigrant raids are scenes where protesters stand around a fiery Waymo. Historically, the first responder without air protection that was supplied developed throat burns and difficulty breathing upon arrival at a scene burning lithium-ion batteries. Depending on the hydrogen fluoride level, the exposed person can begin coughing blood within minutes. On the other hand, inhaling concentrations above about 30 parts (ppm) is immediately dangerous to health. 50 ppm can be fatal if inhaled for 30 minutes to an hour.according to the US Centers for Disease Control and Prevention. The Environmental Protection Agency estimates that 10 minutes of exposure to 170 ppm could be fatal. Measurements taken near the fire in an electric vehicle (EV) show peaks of 150-450 ppm, with most of the fires at levels of about 50 ppm.

Firefighters call such flames “battery box fires” and dislike them. Flame return agent bubbles were of little use and fire departments began to prefer high-pressure water spears or immersion pits. Absorbing a runaway battery usually means lowering the temperature below the runaway threshold for each last battery cell. According to a 2021 interview with Austin Fire Station’s Thayer SmithIt can swallow 30,000 to 40,000 gallons (approximately 114,000 to 151,000 liters) of water. This is at least 40 times the amount of water needed to put out a gasoline vehicle’s fire. If you lightly hit a flame, the energy you’re stuck on will rekindle after hours – the flagged National Traffic Safety Commission in it will shake Report on EV Fire Hazards in 2020.

Automotive designers have tried to deal with the dangers. The software monitors the temperature of the cells and slows down the speed at which the battery is charged to prevent overheating. And if something looks strange, it automatically reduces the current. But even the best code can’t rewrite chemistry. In 2023, the Jaguar recalled more than 6,400 I-Pace cars after igniting at least a dozen overheated batteries. Within minutes of the car unplugged, six fires broke out while the car was connected. Waymo’s fleet has gotten an update to better adjust the battery, but the software doesn’t help when someone crushes one of the car’s windows and lights up the interior with a “make-up flamethrower.” reported by Los Angeles Times.

Was the Waymo van on fire completely? Only with great effort. The company’s previous Chrysler Pacifica Hybrid was phased out in 2023, storing a tenth of its battery energy in steel shells. Steel still recognizes the corpse after a typical flame, as it holds its shape above 1,300°C. To prevent thermal runaways, Teslas has a battery that uses thousands of small cylindrical cells locked inside an aluminum tray with titanium undershields and built-in fires. Also, most brands of electric vehicle batteries are located in similarly rigid aluminum or steel boxes, shifting to less volatile chemicals.

Importantly, however, the Los Angeles scene never shows that electric cars are tinder boxes. In a 2023 survey in Finland, they have miles for miles, I set it on fire few In many cases, it is more than gasoline vehicles. However, when the EV burns, physics changes. No more fighting petrol puddles on asphalt. It is fighting a battery of high energy density metal oxides and is deciding to complete what it started. In such cases, a single Molotov cocktail can transform a sophisticated Robotak into a pool of molten alloys.