"This is really the first time we had flooding in an area with a lot of electric cars," said John Linkov, deputy auto editor for Consumer Reports. Florida has the second-highest number of EVs in the nation after California.

Americans have had more than 100 years to get used to the safety issues gas-powered vehicles can pose. Now there is a learning curve for vehicles powered by batteries, said Thomas Barth, chief of the special investigations branch of highway safety at the National Transportation Safety Board.

"I don't want to give the impression the sky is falling," he said. "But they have their own set of dangers."

Why do flooded EVs catch fire?

If an electric vehicle's battery is damaged by a collision or water intrusion from a flood, a short circuit can occur, which causes the cell to discharge energy and heat up. This can lead to an event called "thermal runaway," in which the heat propagates from one cell to the next, causing them to burn.

In a small number of cases when an EV is submerged in water, contaminants or salt in the water can cause short-circuiting, especially after the water drains from the battery.

Vehicles or batteries that have been damaged also have the potential for short-circuiting to occur due to movement of the vehicle or battery, for example when it's being loaded or unloaded from a tow truck.

Heat generated from a fire, thermal runaway of an adjacent cell, or shorting of the battery can melt the porous membrane between the battery's cathode and anode, causing this cell to go into thermal runaway. The heat causes the cell to vent flammable gas, which can ignite and catch fire.

"That heat can get transferred to the next cell and it can become a chain reaction," said Barth.

"If you have a damaged lithium-ion battery and it has energy which remains in the battery pack, we call that stranded energy," he said. "If you initiate a thermal runaway or venting of the flammable gas, the battery can ignite."

Did a high percentage of the EVs in Florida burn?

Social media posts claiming EVs catch fire "often" overstate the problem, say experts.

Collier county, which includes the city of Naples, had 2,490 electric vehicles registered as of July 2021, said Stan Cross, electric transportation policy director for the Southern Alliance for Clean Energy.

That would mean a fraction of a percent of the EVs in the county caught fire after the flooding.

In Lee county, where Sanibel Island is located, there were 2,683 EVs registered last year. The one EV that burned there would mean less than 0.04% of the electric vehicles in the county caught fire.

There was also a report by the local paper, the Island Reporter, that several flooded electric golf carts at The Dunes Golf & Tennis Club also caught fire, on Oct. 16.

What should I do with a flooded EV?

Electrical corrosion may not be visible, and an EV can experience thermal runaway hours or even days after flood waters recede.

This means flooded EVs parked in garages or carports next to homes should be moved away from buildings. These cars should not be driven but must be towed. Experts cautioned that no car, whether electric of gas-powered, should be driven after flooding until it has been checked out by a professional.

"No road vehicle should be considered roadworthy after saltwater flooding, whether it's an EV or anything else," said Haresh Kamath, director of distributed energy resources at the Electric Power Research Institute in Palo Alto, Calif. "If you've experienced saltwater flooding, you should not be driving or trying to drive or even start that vehicle. You shouldn't be getting into the vehicle."

On Sanibel Island, which was heavily damaged by Ian, Sanibel Fire Rescue District crews have towed between 20 and 25 electric vehicles from garages or under residences to prevent possible structure fires, the agency said in a Facebook post.

The cars are being moved at least 15 feet away from buildings.

Are EV fires hard to put out?

EV fires are more difficult to put out than ones in gasoline-powered cars and require different firefighting techniques, say experts.

Firefighters are already training on how to deal with EV battery fires, said Andrew Klock, senior manager of product and development for the National Fire Protection Association.

The biggest difference is that an EV fire cannot be put out with the type of firefighting foam used to smother other fires. Instead, the battery must be cooled to stop the fire and end thermal runaway, he said.

"Lithium-ion batteries generate their own heat and oxygen," said Klock. To stop the fire requires putting water on the battery case to cool it.

Most EV batteries are underneath the vehicle, so pouring water on top of the car or in the engine compartment is not helpful, he said.

"You need to get the water underneath," said Klock, whose organization provides training materials for fire departments on how to deal with all types of fires.

All car and truck manufacturers are already required to create emergency response guides for first responders on how to deal with everything from safely extricating someone from a crashed car to high-voltage disconnect instructions.

A 2020 report by the National Transportation Safety Board found that more information about dealing with battery fires was needed.

"We've had excellent response from that guidance, a lot of the vehicle manufacturers have rewritten their emergency response guides or are in the process of doing that," Barth said.

In addition, a group of federal, state and private company experts has come together to address the issue of EVs and hurricanes and are working on it now, he said.

Aren't there protections built into the batteries?

EV batteries are specifically engineered to make thermal runaway "very, very rare," said Kamath.

"The safety systems inside a lithium-ion battery generally prevent that type of thing happening unless there is some significant physical damage to that battery," said Kamath, who has worked on battery issues for more than 20 years.

In the case of a crash, modern electric cars are designed with fuses that are triggered if the airbags deploy, said Barth.

"Essentially, they're cutting the high voltage lines to the motor that turns the wheel," he said. "If you crash, you don't want the high voltage lines powered up that could energize the chassis and shock someone."

EV batteries are designed with seals to protect against water intrusion, said Stu Fowle, a communications director with General Motors.

"Our tests include extremely dry conditions and water submersions to simulate flooding, validating the safety and isolation of systems," he said in a statement to U.S. TODAY.

The fact that only eleven EV fires have been associated with Hurricane Ian is telling, said Marc Geller, with the Electric Vehicle Association.

"If a ton of flooded EVs were catching fire, we'd certainly hear about it," he said.

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

If the car itself wasn't flooded, then yes, it is safe to charge.

If the charging station flooded, it shouldn't be used—and will not work, said experts. The safety mechanisms built into any system that flooded should have automatically shut it off, said Kamath.

"They have done a lot of engineering to make sure that in the event of flooding or something that would interfere with the operation, the system shuts down," he said.

Are flooded conventional cars ok?

No vehicle, whether powered by gasoline or a battery, is safe to drive after being flooded, multiple experts warned.

"Just like flooding is the end of the road for a gasoline-powered car, it's the end for electric cars too," said Brian Moody, executive editor for Autotrader.

"Many of the same problems that plague a gasoline-powered car are an issue no matter how the car is powered. The dash, gauges, heating system, brakes, wiring, seats, radio, touchscreen, all those components will be ruined by water, especially salt water," he said.

Better driver education for EV owners

Electric vehicles are increasingly popular in the United States, reaching a record 5.6% of all new cars sold in the United States in the third quarter of 2022, according to Kelley Blue Book. In 2021, there were 321,546 EVs sold in the U.S. So far this year the number stands at 546,664, according to Kelley Blue Book.

Estimates put the number of electric vehicles on U.S. roads at somewhere between one and two million. That's a far cry from the 286 million total cars registered, but does mean an increasing number of Americans are driving battery-powered vehicles. There's a learning curve, say experts.

Florida has the second-highest concentration of electric vehicles after California, said Cross. As the state, and the nation, face the possibility of more floods, getting new EV owners up to speed will be necessary.

Most Americans grew up with gas-powered vehicles and have at least some understanding of their dangers—even if it's only having seen movies where a gas leak from the tank of a damaged car precedes a billowing cloud of flame.

With so many new EVs on the road, and drivers new to electric vehicles, learning about their differences is important.

"With all new technologies, there will be problems to work out. With EVs, though the problems are few, they are headline-catching and life and property-threatening," said Cross. "You can't hide from that. It's a problem, it needs to be addressed."

(c)2022 USA Today
Distributed by Tribune Content Agency, LLC.