As hybrid and electric cars rise in popularity throughout the U.S., so does the prospect of car fires stemming from the lithium-ion batteries that power “green” engines.
Firefighters in Mountain View, California, responded last week to an electric car battery fire. According to the Mountain View Voice, the car’s engine had been converted from a conventional combustion engine to all-electric. For unknown reasons, a lithium-ion battery in the engine overheated to about 500 degrees, casting a plume of noxious smoke.
It was the first electric car battery fire the Mountain View Fire Department had to battle, the Mountain View Voice reported. Firefighters consulted a material safety data sheet and chose to use carbon dioxide extinguishers rather than water to bring the fire under control.
The process involved emptying several extinguishers to cool the battery down to 250 degrees and suffocate the oxygen around the battery. The car required supervision all night after the fire was extinguished because lithium-ion batteries have a tendency to reignite hours later. In some cases, the powerful rechargeable batteries can suddenly combust again days and even weeks later.
The process of extinguishing a large lithium-ion battery fire was a learning one for the Mountain View Fire Department. Although the carbon dioxide extinguishers worked, Andrew Klock, senior project manager at the National Fire Protection Association (NFPA), told the Mountain View Voice that water would have been fine to use.
Mr. Klock told the Voice that the association recommends using water to put out vehicle fires, regardless of whether it’s an internal combustion engine, hybrid, or all-electric car.
Mr. Klock said that the NFPA tested extinguishing high-voltage lithium-ion and nickel-metal-hydride batteries with water, and in all cases it proved to be a safe method. However, firefighters will need at least two truckloads of water or access to a fire hydrant to extinguish one rechargeable car battery fire.
“If you can’t establish a sustained water supply, there’s a high likelihood the battery will reignite,” Mr. Klock told the Mountain View Voice. “You won’t be doing any good if you don’t have enough water to cool down the battery and extinguish it.”
Although firefighters don’t know what caused the car battery in Mountain View to combust, defects in the battery, damage, or improper use can all lead to overheating, just as their smaller counterparts have done in electronic cigarettes, hoverboards, laptop computers, and other consumer devices.
Source: Mountain View Voice