Electric Car Fires Are Uniquely Dangerous
Oct 14, 2021 · 4 min read
When the high-voltage, lithium-ion batteries used in electric vehicles (EVs) catch fire, they are extremely difficult to extinguish. As the popularity of EVs begins to soar, there are concerns that fire departments across the country are unprepared for the associated risk.
Read on to learn what makes electric car fires so uniquely dangerous, what Tesla and other automakers are doing to help, and what can be done to solve this problem.
Why are electric car fires so dangerous?
You may remember the news of Galaxy Note 7 phones spontaneously catching fire a few years ago. The problem was blamed on lithium-ion batteries, which have the potential to overheat, explode, and burn.
As reported by Popular Science, the same technology is used in electric car batteries, but these are far larger and contain a lot more stored energy than the batteries used in phones.
The battery in the Tesla Model S for example, contains over 7,000 individual cells. A flammable electrolyte carries trillions of charged ions through the battery, and if the battery is damaged, an internal short-circuit could unleash a huge amount of stored energy.
If there is a spark the battery will quickly ignite. While burning, the stored energy within the lithium battery acts as a fuel source, making it very difficult to put out the fire. It’s the equivalent of trying to extinguish a bonfire with a hose, while someone else continues to pour gasoline on the flames.
Fire departments struggle to extinguish EV fires
Fire departments have not been properly trained on how to put out EV fires, and are often ill-equipped to deal with their ferocity. Quoted by NBC News, Chief Palmer Buck of The Woodlands Township Fire Department compares them to "trick birthday candles" which just keep reigniting.
Proving his point, a Tesla Model S fire in Houston recently required seven hours and 30,000 gallons of water before it finally went out. Compare this to a fire from an internal combustion engine fire, which can normally be extinguished with 300 gallons, and it’s clear that fire departments are dealing with an entirely new threat.
One problem is that water can exacerbate a lithium battery fire by acting as a conductor between the cells, so firefighters can actually make the fire worse by hosing down a burning EV.
These fires require either an exorbitant amount of water, or ideally, powdered graphite to put them out. Unfortunately, most firehouses don’t have this at hand.
How common are electric car fires?
Tesla claims that gas cars are about 11x more likely to catch fire than one of its models, and experts largely agree with them. The problem is that when electric cars do catch fire, the duration and intensity of the flames are far more dangerous.
Most electric car fires happen after crashes, but there have been instances of EVs catching fire while charging, and in one case, a Model S went up in flames while sitting in traffic in downtown L.A.
In a statement, Tesla called it "extraordinarily unusual," but they are working to help fire departments better prepare for such occurrences.
What has Tesla done about the issue?
In an attempt to help them confront battery fires, Tesla has released a guide for first responders. Regarding the Model 3, Tesla advises using "large amounts of water," carbon dioxide, or "dry chemicals."
But according to NBC, fire department officials don’t feel like they have enough information. For example, Tesla's manual provides little detail about what firefighters should do with the remains of damaged batteries. Even if the fire is out, they might still contain dangerous amounts of flammable energy.
Firefighters also struggle to transport the required amount of water to the scene of an electric car fire, especially if it is in a rural area, or the middle of a highway. Tesla hasn't offered a suggestion on how to get around this.
How can this problem be solved?
Popular Science points to a company called QuantumScape in Silicon Valley, which is developing a solid-state electrolyte lithium battery. If successful, this could revolutionize lithium batteries, rendering them as safe as the AA batteries used in small electrical appliances.
Some skepticism remains about the viability of this plan, but experts agree that with so much riding on electric vehicles, engineers will eventually find a solution.
Firefighters across the nation will hope that an engineering breakthrough happens sooner rather than later though, with as many as one in ten American drivers expected to go electric by 2025.