Electric-Car Fires Prove Hard to Put Out --- Vehicles combust differently; blazes last longer and have tendency to reignite.

"Firefighters called to extinguish an electric-vehicle fire are discovering the surest approach is to stand back and watch it burn.

Electric cars combust differently than their gas-powered counterparts. Firefighters and researchers said EV fires last longer, are harder to put out and have a tendency to reignite.

First responders in Franklin, Tenn., faced their first burning EV in September, a Nissan Leaf that ignited while charging outside the car maker's North America headquarters. They spent hours pouring 45,000 gallons of water on the car, compared with the 500 to 1,000 gallons that fires involving gasoline-powered vehicles usually need, Fire Marshal Andy King said.

"I think if we were faced with a similar scenario next time, we might need to let it burn," he said.

Nissan said it is investigating the cause of the fire.

It isn't clear how frequently EV fires take place, but as the cars become a larger part of the American fleet, some fire departments see them as a growing nuisance. 

Firefighters in Florida's North Collier Fire Control and Rescue District responded to six last year after a storm surge brought by Hurricane Ian caused saltwater to get into EV battery compartments, which can cause short-circuits.

There are more than 170,000 vehicle fires in the U.S. each year, but the National Fire Protection Association doesn't break them out by power source. 

Tesla estimates its cars catch fire at a rate much lower than U.S. vehicles overall, and some independent studies have reached similar conclusions about EVs in general.

First responders are still trying to figure out how to deal with EV fires. "When we look at how much money is going into battery plants, into the EV transition, there hasn't been that carve-out to prepare the fire service," said Michael O'Brian, fire chief of Michigan's Brighton Area Fire Authority and chair of the International Association of Fire Chiefs' battery committee.

Electric-vehicle fires usually start in the car's lithium-ion batteries, which can store a massive amount of energy. If a battery is poorly designed, or if it is damaged by shock or internal spikes of lithium that form over time, a process known as "thermal runaway" can begin, said chief scientist Robert Slone of UL Solutions, which tests and certifies batteries.

The batteries contain flammable chemicals and can release their own oxygen as they burn, allowing EV fires to reignite hours or even days after they appear to be quenched. They also emit toxic fumes that Tom Miller, who teaches for the West Virginia University Fire Service Extension and the National Volunteer Fire Council, said "make hydrogen cyanide look like Pez."

Genevieve Cullen, president of the Electric Drive Transportation Association industry group, said electric vehicle fires aren't more dangerous than those involving gas-powered vehicles, but do require their own tactics. "It's a matter of training," she said.

Motorists tempted to tackle an EV fire themselves should think twice, O'Brian said. A fire extinguisher would likely be incapable of tamping down the flames from a battery pack, he said, and the smoke is highly dangerous. He said drivers should pay attention to any indications a problem might be coming. "If the dash is telling you, 'Don't drive the car, pull over' -- pull over and stop driving the car," he said.

Some departments take a cautious approach. Firefighters in Hillsborough Township, N.J., allowed a Tesla that had been in an accident to burn itself out after it ignited in a salvage yard last month. The Cosumnes Fire Department in California did the same in May with a Tesla near Sacramento.

That car's owner, Bishal Malla, said it began vibrating harshly as he drove onto a highway ramp. Thinking he had a flat tire, he stopped and got out, only to see smoke billowing from the undercarriage. Within minutes, he said, the smoke became flames.

A responding fire engine sprayed about 700 gallons of water on the fire, but when it was clear that the batteries were involved, Assistant Fire Chief Robert Kasparian told his firefighters to let it go. Tesla didn't respond to a request for comment.

Kasparian said letting an EV burn isn't always possible. He and his colleagues are trying to figure out how they would deal with an electric car that combusts in the owner's garage. He said one idea is to hit the fire with a "fog stream," which is a fine spray rather than a jet of water. That could lower the temperature enough so a firefighter could hook a chain to the car and drag it outside.

New products aimed at taming EV fires are coming onto the market. The Louisville Fire Department in Kentucky has a specialized nozzle designed to slip under a car and spray water directly onto the undercarriage, cooling the battery pack. Others use large blankets meant to smother the flames.

Audi has filed a patent application for a battery that can extinguish its own fire. Industrial conglomerate Honeywell and energy company Nexceris are creating early warning sensors for batteries, and 3M is working on materials meant to contain thermal runaway." [1]

1. U.S. News: Electric-Car Fires Prove Hard to Put Out --- Vehicles combust differently; blazes last longer and have tendency to reignite. Keilman, John.  Wall Street Journal, Eastern edition; New York, N.Y.. 11 Nov 2023: A.8.