Lithium-Ion Battery Fires: What Every Firefighter Needs to Know

We’ve been training on structural firefighting fundamentals for decades. And those fundamentals still matter. But lithium ion battery fires don’t play by the same rules, and departments that approach them the same way they’d approach a conventional vehicle fire are going to get caught off guard.

I want to break down what makes these fires different, what tactics are actually working, and what every firefighter, and every candidate preparing to enter the service, needs to understand about this emerging hazard.

What Makes Lithium Ion Battery Fires So Dangerous?

The core hazard is something called thermal runaway. Once it starts, it’s very hard to stop.

Here’s what happens: when a lithium ion cell is damaged, overcharged, or exposed to extreme heat, it starts to degrade internally. That degradation generates more heat. More heat degrades more cells. More cell degradation generates more heat. The chain reaction becomes self sustaining, and individual cells can reach temperatures above 1,000°F during the process.

What makes this especially dangerous is that the battery produces its own oxygen during thermal runaway. Standard suppression strategies that work by removing oxygen from the equation don’t work here. You can’t smother a lithium battery fire.

What Are the Specific Hazards for Firefighters?

Reignition

A battery fire can appear fully extinguished; no visible flame, no smoke, and then reignite hours later, sometimes after a vehicle has been towed to an impound lot or a battery pack moved to a staging area. Departments that cleared scenes too early have come back to second fires that were larger than the first.

Toxic Gases

Thermal runaway releases a mixture of highly toxic gases including hydrogen fluoride, carbon monoxide, and various hydrocarbons. Crews who weren’t in full SCBA during overhaul have reported skin and respiratory irritation afterward. This is a scene where you stay masked up until you’re sure.

Contaminated Runoff

The large volumes of water required for suppression create contaminated runoff that can’t just drain into the street or a storm system. Containment is an environmental and a liability issue that departments are still figuring out how to address at scale.

How Do You Fight a Lithium Ion Battery Fire?

The honest answer is that the fire service is still writing the playbook on this. But here’s what’s working:

• Water, and a lot of it. The primary suppression strategy is extended water application directly to the battery pack. Some departments have used 8,000 gallons or more on a single EV fire. The goal isn’t to extinguish thermal runaway; it’s to cool surrounding cells and slow the spread of the reaction.
• Submersion. Some departments and salvage companies now use purpose built tanks or lined dumpsters filled with water to fully submerge burning battery packs after initial knockdown. Submersion has proven effective for preventing reignition.
• Thermal imaging throughout. TIC cameras are essential for monitoring battery temperature after apparent knockdown. A pack that looks controlled on the outside may still be undergoing internal thermal runaway. Don’t clear the scene without it.
• Greater standoff distances. Active thermal runaway can produce sudden pressure releases or small explosions. Many updated protocols now call for larger standoff distances than you’d use for a conventional vehicle fire.

The E Bike Problem

EV fires get the attention, but e bikes and e scooters may be the more immediate hazard for most departments right now, especially urban ones. Small lithium packs, often cheaply made with minimal safety regulation, are charged overnight in apartments, hallways, and parking garages. When they fail, they ignite fast and cut off egress routes before occupants can get out.

New York City documented over 260 lithium battery fires in 2023. That’s a structural fire problem showing up with the regularity of a medical call problem.

What Candidates Need to Know

Lithium ion battery response is part of the job now, whether you end up in a major urban department or a small rural company. During your hiring process, it’s worth asking departments how they train for EV and battery fires. It tells you something about how seriously they take emerging hazards and how much they invest in preparing their crews for what’s actually on the street.