SIOUX FALLS, S.D. (KELO) — A company that manufactures fire engines in Lyons, South Dakota, also produces a device which it bills as the key to extinguishing electric vehicle (EV) fires.
When an EV recently caught fire near Vermillion, S.D., local firefighters did the only thing they could. They closed the highway and sprayed water at it over the course of several hours while patiently waiting for the fire to burn itself out.
The result? A puddle of car.
“The smoke is very toxic,” said Ernie Young, Battery Extinguisher System Technology (BEST) Specialist for Rosenbauer America, the manufacturer of the BEST system.
“We can cover them up. We can spray water to keep things cool for extended periods of time, but to actually extinguish the fire, this is the only product on the line,” Young said.
That first method, to “cover them up”, highlights an important fact about EV fires.
“There are fire blankets out there to cover vehicles, and the idea behind that is we’re gonna smother the vehicle and take away the oxygen,” Young said. “With an EV fire, the products of combustion with a lithium ion battery is to emit oxygen and hydrogen.”
Due to this, smothering an EV fire does not work, as the battery creates oxygen to feed the fire as it burns.
Simply allowing the fire to burn itself out has various drawbacks.
As noted, the smoke produced by a burning EV is toxic. “Allowing all that smoke for hours to emit into the atmosphere,” said Young, listing the downside to a burnout. “They apply copious amounts of water while not putting out the fire — these batteries are self-sustaining.”
Cooling an EV fire with water in the traditional way takes time and lots of water. Rosenbauer cites EV manufacturers as recommending as much as 8,000 gallons of water at a minimum over the course of several hours to properly stifle an EV fire.
Young says the BEST device can put out the fire in around 45 minutes, using less than 500 gallons of water.
The device comes in three pieces; the control unit, the head unit and the hose unit.
The machine, slid into place under the car, uses 600 psi of pressurized air to punch a spike with up to 10,000 psi of force through the underside of the battery pack before flooding it with water from the inside. How much water? Young says about eight gallons/minute, which is less volume than a garden hose.
Young says the decreased volume of water needed can be especially important when a car catches fire out on a highway. “There’s no hydrant, so we’re doing water shuttling for hours.”