'Thermal Runaway': Firefighters explain why lithium-ion battery blazes are so hard to extinguish

Oct 19, 2024

Published:

So far this year, a number of lengthy road closures in California and Nevada have been caused by crashed trucks carrying lithium-ion batteries.

Why are these battery fires so tough for firefighters to extinguish? Because of a phenomenon called “thermal runaway.”

In the last few months, a number of fiery high-profile truck crashes involving lithium-ion batteries have made national headlines.

On July 26, a semi truck hauling lithium-ion batteries overturned on near I-15 the Nevada/California state line, shutting down the interstate. The batteries burned for days following the crash.

On August 19, a battery-powered Tesla Semi crashed on I-80 near, Emigrant Gap in Placer County, California. The truck caught fire, spewing “toxic fumes,” and triggering a National Transportation Safety Board investigation that determined that it took 50,000 gallons of water to put the fire out.

Another major truck crash involving lithium-ion batteries occurred on September 17 near Indian Springs, Nevada at mile marker 13 on Highway 95. One of the trucks involved was hauling wood; the other was hauling 31,000 pounds of lithium-ion batteries. This crash also sparked a major fire and lengthy road closure.

The truck crashes and subsequent lithium-ion battery fires have become such a problem that in September, Nevada Rep. Dina Titus introduced the “Thermal Runaway Reduction Act” to strengthen federal regulation of the transport of lithium ion batteries.

Following the July 26 incident, San Bernardino County Fire provided a detailed description of how thermal runway works and why it’s so dangerous:

Thermal runaway is a chain reaction within a lithium-ion battery that can lead to catastrophic failure, resulting in fires or explosions.

Here’s a step-by-step breakdown of what happens during thermal runaway:

Firefighters also detailed why these thermal runaway incidents are so dangerous: