A recent assessment by the National Transportation Safety Board (NTSB) has spotlighted the first-ever fire involving a Tesla Semi truck, revealing some dramatic findings. While conventional internal combustion engine (ICE) vehicle fires typically require up to 1,000 gallons of water to be extinguished, the story is vastly different for electric vehicle (EV) fires. Due to the nature of lithium-ion batteries, which have a propensity to reignite, Tesla advises that up to 8,000 gallons may be necessary to douse an EV fire when water is applied directly to the battery. However, the Tesla Semi’s massive 900 kWh battery pack proved even more challenging.
On the early morning of August 19, a Tesla Semi swerved off the road in California, collided with a tree, and tumbled down a slope, eventually crashing into a forest. Following the accident, the truck’s lithium battery ignited. Thankfully, the Tesla driver managed to escape unharmed. The vehicle’s fiery fate grabbed headlines as the blaze took an astounding 50,000 gallons of water—50 times the usual amount needed for an ICE vehicle—to finally extinguish it.
The incident caused significant disruption, as the California Highway Patrol, CAL FIRE, and Caltrans had to reroute traffic on the busy I-80 freeway. To combat the blaze, Tesla quickly sent a high-voltage fire hazard safety specialist to the scene. This expert instructed firefighters to use scanners to continuously monitor battery temperature and air quality, ensuring a meticulous oversight of the evolving situation.
According to the NTSB report, “Traffic on I-80 was diverted as emergency responders worked to control the fire, using about 50,000 gallons of water to extinguish the flames and cool the vehicle’s batteries.” In addition, a firefighting aircraft was deployed to spray the area with fire retardant, helping to contain the flames to the accident site.
The crux of the problem with lithium battery fires is their tendency to reignite, necessitating extensive amounts of water and prolonged dousing efforts. Unlike ICE vehicle fires, which can be managed relatively swiftly, EV fires require firefighters to continuously soak the battery cells to prevent rekindling.
This growing challenge has led companies like Rosenbauer to innovate specialized EV fire tools, featuring high-pressure nozzles capable of penetrating battery packs to deliver water directly to the cells. Despite these advancements, the Tesla Semi fire underscores the escalating difficulties fire departments face as electric vehicle adoption grows nationwide.
