Electric Car Fires: What You Should Know

A common cause of electric car fires is damage to the vehicle's battery pack — often from a serious crash. Ruptured battery cells begin to increasingly heat up through chemical reactions and a fire can quickly spread to the rest of the vehicle. If you've been researching electric vehicles to buy, you've likely come across news stories about electric car fires. Those stories can seem scary enough to turn you off on potentially buying an EV, but the truth is that electric cars are less likely to catch fire than traditional gas-powered vehicles. This article will help you understand what causes EV fires, just how common they are, and what you should do if you experience one.

When you hear that an internal combustion engine vehicle has caught fire, most people rarely bat an eye; it makes logical sense. Combustion is right in the name, engines are hot, and you carry around gallons of wildly flammable gasoline. It's a fire just waiting to happen.

With EVs, there's no tank of explosive fuel and, compared to a gasoline or diesel engine, electric motors don't generate that much heat. So why then do they catch fire?

In short, it's chemistry. The chemicals and elements that make up the individual cells inside an electric vehicle's battery pack are very sensitive. This is especially true with the lithium-ion chemistry that most modern EVs use. If an EV is in a very serious crash and the battery pack is compromised, battery cells can rupture, and they will heat up until they hit a point called "thermal runaway."

Thermal runaway occurs when a battery's cells get so hot that chemical reactions begin to occur, and the heat, in most cases, continues to increase uncontrollably. At this point, the cells can catch fire, which cascades throughout the pack until you have an EV burning to the ground.

Battery cells that are improperly charged or balanced can also cause thermal runaway. Lithium-ion battery packs are very sensitive to how they are charged. Each cell in the battery module needs to be charged to a level similar to its neighbors or it could overheat, and again you can get thermal runaway and a crispy car.

Modern electric cars cool their battery packs in one of two ways to help mitigate the risk of thermal runaway and to help the pack function at its most efficient. Older EVs and less expensive EVs tend to use air cooling. This means that the enclosure for the battery pack is built to dissipate heat as air moves over it. Higher-end EVs use a liquid cooling system that circulates coolant throughout the cells via a radiator and fans to dissipate the heat stored there, similar to the radiator in a gas-powered car.

If you're only looking at news reports, you might think that electric car battery fires are common. That's likely because EVs are still relatively new, and because the fires can be tough to fully extinguish, they tend to get a lot of coverage. Gas-powered vehicles catching fire aren't as newsworthy because that's been happening for over a century.

Finding out exactly how many EVs catch fire every year in the U.S. isn't currently possible because there isn't a government agency keeping track of it — at least not publicly. Luckily, Sweden's Authority for Social Protection and Preparedness, or MSB, is doing so and we can use those figures to make some educated guesses.

The MSB's 2023 report found that electric car fires, out of about 611,000 electric vehicles, have averaged about 20 per year in the last three years. On the other hand, cars powered by fuel — totaling about 4.4 million — had about 3,400 fires during that same time. The agency concedes that some of the fires in internal combustion engine vehicles were due to arson, but the figures still come out in favor of EVs.

Similarly, Australia's EV FireSafe, a group funded by the country's department of defense, studied global EV battery fires from 2010 to 2020. The report found that the risk of an electric car battery catching fire was a thousandth of a percent (0.0012%). FireSafe noted that it was difficult to find similar data for internal combustion engine vehicles globally, but based on the reports the group looked at, it estimated fire risk at a tenth of a percent (0.1%).

For comparison, the U.S. had over 283 million registered vehicles in 2022, so the odds are good that you'll never have to worry about your new electric car bursting into flames. But what if the odds are against you and you do experience a lithium fire?

If you're the type of motorist who insists on carrying a fire extinguisher with you in your car, you might be wondering what kind you need to buy for an EV. Unfortunately, there simply isn't one.

If your EV catches fire or if you see someone else's EV ignite, the best thing to do is to call the fire department. Not only is a lithium fire hard to extinguish in the first place, they are extremely prone to reigniting out of nowhere, sometimes days after the initial fire. Add in that the smoke from an EV fire is especially toxic, and you're better off just getting to a safe distance and letting the professionals handle it.

FireSafe notes that there are three generally accepted types of EV fire suppression. The first is to try to cool the fire down. This is similar to extinguishing a house fire, but in this case firefighters spray water on the burning vehicle to lower its overall temperature. This approach has the downside of using vast quantities of water and creating a lot of potentially toxic runoff.

Next is letting the fire burn itself out. This method is quick and reasonably efficient but releases a lot of toxic fumes into the air as the car burns. Plus, there won't be much left of the car when the flames have subsided.

Lastly, you can submerge the burning vehicle. With this approach, firefighters can put the burning vehicle into a huge metal container filled with water. While this method eliminates the toxic runoff issue and is generally more effective than just spraying it with water, the vehicle may need to be kept in the container for weeks to ensure that it doesn't reignite and it still uses a lot of water.

An electric car fire can be difficult to extinguish, but they tend to occur far less than fires in gas-powered vehicles. Don't let a few news reports scare you away from going electric in your next vehicle purchase.