Why Do Teslas and Other EVs Catch on Fire?

Here's What You Need To Know About EVs Catching on Fire

According to the experts, Tesla cars have lithium-ion batteries that may pose a risk of fire and explosion if damaged.

Hurricane Ian caused flooding in Florida that led to a few electric vehicles catching fire. This incident has brought attention to a safety concern that many Americans who own or plan to own an electric vehicle were not aware of before. It has also sparked political debate, with some Florida Republican lawmakers advocating for more regulation of electric vehicles. Florida's State Fire Marshal, Jimmy Patronis, expressed concern on Twitter about the safety of electric vehicles during floods. However, experts point out that all vehicles, regardless of their power source, have the potential to ignite due to concentrated power sources.

According to data collected by AutoInsuranceEZ, there are approximately 25 fires per year for every 100,000 electric vehicles (EVs), whereas there are 1,530 car fires per year for the same number of gas-powered vehicles. Gas-powered cars usually catch fire due to fuel leaks or accidents.

On September 28th, Hurricane Ian hit the Gulf Coast of Florida, resulting in a devastating loss of life. A total of 118 people lost their lives in Florida, while four others lost their lives in North Carolina and one in Virginia. In addition, the hurricane caused massive damage, amounting to more than $50 billion. Large areas were also flooded due to the impact of the hurricane.

In Florida, there have been 11 instances of electric vehicles catching fire as a result of flooding caused by Hurricane Ian. It is believed that these fires occurred due to the battery packs of the cars shorting out after being submerged in saltwater or sustaining physical damage during the flooding.

Experts have been aware of the risk of fire from flooding in electric vehicles (EVs) since Superstorm Sandy in 2012. However, Hurricane Ian has brought this issue to the forefront for the general public.

Over the past century, Americans have become accustomed to the safety risks associated with gas-powered vehicles. However, there is now a learning curve when it comes to vehicles powered by batteries, according to Thomas Barth, the chief of the special investigations branch of highway safety at the National Transportation Safety Board.

Why do flooded EVs catch fire?

If an electric vehicle's battery is damaged by collision or water intrusion, it can lead to a short circuit that discharges energy and generates heat. This can cause "thermal runaway," where heat spreads from one cell to the next, resulting in cell combustion.

Flooded Tesla

In some cases, when an EV is submerged in water, contaminants or salt in the water can cause short-circuiting, particularly after the water drains from the battery.

Furthermore, vehicles or batteries that have been damaged have the potential for short-circuiting due to movement, such as when being loaded or unloaded from a tow truck.

The heat generated from a fire, thermal runaway of an adjacent cell, or shorting of the battery may cause the porous membrane between the battery's cathode and anode to melt. This can lead to thermal runaway, where the cell vents flammable gas that can catch fire. The heat can spread to the next cell, creating a chain reaction.

Tesla battery pack.

If a lithium-ion battery is damaged and still has energy remaining in the pack, this is known as stranded energy. If you start a thermal runaway or vent the flammable gas, the battery can catch fire.

What should I do with a flooded EV?

It's important to note that electrical corrosion may not be easily noticeable and in some cases, an EV may experience thermal runaway hours or even days after flood waters recede. If you have a flooded EV parked in a garage or carport next to your home, it's recommended that you move it away from the building. It's important to avoid driving these cars and instead have them towed. Experts advise that all cars, whether electric or gas-powered, should not be driven after flooding until they are checked by a professional. 

It's not safe to consider any road vehicle roadworthy after it has been exposed to saltwater flooding, including electric vehicles. If your vehicle has suffered saltwater flooding, avoid driving, attempting to drive, or starting the vehicle altogether. It's best to avoid getting into the vehicle.

Sanibel Island was badly affected by Ian, resulting in the towing of 20 to 25 electric vehicles from garages or beneath homes by Sanibel Fire Rescue District crews to prevent potential structure fires. The cars are being relocated to a distance of at least 15 feet away from buildings, as per the agency's Facebook post.

Are EV fires hard to put out?

According to experts, fires in electric vehicles (EVs) are harder to extinguish compared to those in gasoline-powered cars. Therefore, firefighters are being trained to use different techniques to manage fires in EV batteries.

Firefighters extinguishing Tesla on fire.

One major distinction is that electric vehicle fires cannot be extinguished using conventional firefighting foam. The fire can only be stopped by cooling down the battery to prevent thermal runaway. This is because lithium-ion batteries produce heat and oxygen on their own. To extinguish the fire, water must be applied to the battery case to cool it down. However, it is important to note that the water needs to be directed underneath the battery as most EV batteries are located beneath the vehicle. Pouring water on top of the car or in the engine compartment will not be effective in putting out the fire.

Car and truck manufacturers are required to create emergency response guides for first responders. These guides cover everything from safely removing someone from a crashed vehicle to high-voltage disconnect instructions. However, a 2020 report by the National Transportation Safety Board found that more information is needed for responding to battery fires. Many vehicle manufacturers have taken steps to update their emergency response guides based on this feedback. Additionally, a group of experts from federal, state, and private companies are working together to address the issue of electric vehicles and hurricanes.

Aren't there protections built into the batteries?

Lithium-ion batteries are designed to minimize the occurrence of thermal runaway, which is a very rare event. The safety mechanisms within the battery are effective in preventing such incidents, except in cases where there is significant physical damage to the battery.

Modern electric cars are designed with fuses that cut the high voltage lines to the motor in case of a crash, to prevent energizing the chassis and potentially shocking someone. EV batteries have seals to protect against water intrusion and undergo extensive testing to ensure safety and isolation of systems in dry and flooded conditions. The low number of EV fires associated with Hurricane Ian, only eleven, is indicative that flooded EVs are not catching fire in large numbers.

Is it safe to charge an EV in a flooded area?

Experts advise that if the car was not flooded, it is safe to charge. However, if the charging station was flooded, it should not be used as it will not work. Safety mechanisms are built into these systems, and they should have shut off automatically in the event of flooding or any interference with their operation. Engineers have invested a lot of effort to ensure that the system shuts down in such situations.

Are flooded conventional cars ok?

According to several experts, driving a vehicle, whether it is powered by gasoline or a battery, after it has been flooded is not safe. Flooding can damage many of the same components in both types of vehicles. This includes the dash, gauges, heating system, brakes, wiring, seats, radio, and touchscreen, which are all likely to be ruined by water, especially salt water. As a result, it is important to avoid driving any flooded vehicle, as it is no longer safe to operate.

Proper education for EV owners

Kelley Blue Book reports that electric vehicles are becoming increasingly popular in the United States, accounting for a record 5.6% of all new cars sold in the third quarter of 2022. In 2021, there were 321,546 EVs sold in the U.S. and the number has now risen to 546,664. While electric vehicles on U.S. roads are estimated to be between one and two million, this still signifies an increasing number of Americans driving battery-powered vehicles. However, as experts note, there is a learning curve for those who are new to EVs. Florida has the second-highest concentration of electric vehicles after California, and as the possibility of more floods looms, it is essential to get new EV owners up to speed.

As most Americans grew up with gas-powered vehicles, it is important for drivers to learn about the differences between these two types of vehicles. Although the problems with EVs are few, they can be headline-catching and life-threatening, so they must be addressed.

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