Fire chief: Tesla battery caught fire again six days following deadly crash

Quimby Mug Bayou Florida
Updated May 12, 2018

The Tesla Model X involved in a deadly and fiery car crash in March in Northern California has firefighters there on edge according to a memo from a fire chief this week who reports, among other things, that the car’s battery caught fire again nearly a week after the crash.

The news comes just after a deadly Tesla Model S accident in Ft. Lauderdale this week which left two teenagers dead and one hospitalized. After the car slammed into a wall it began burning. Witnesses said they saw the two 18-year-old high school seniors struggling in vain to escape the flames, according to ABC News. The passenger who survived the crash had been thrown from the vehicle.

Both the National Transportation Safety Board and the National Highway Traffic Safety Administration are investigating. Autopilot was not engaged at the time of Tuesday’s crash.

EV battery fires have Mountain View Fire Department Chief Juan Diaz seriously concerned. In a 13-page safety alert, Diaz wrote about the challenges of dealing with an EV battery fire, which includes having enough water handy to douse hot and unstable cells following an accident.

When responding to the Tesla crash in Mountain View on March 23 that claimed the life of 38-year-old Apple engineer Walter Huang, Diaz notes that his tanker truck had 500 gallons of water while Tesla recommends using 3,000 gallons of water to keep damaged cells cool following a high-impact collision.

“The battery began to overheat even though we had already cooled the battery and it continued to reignite,” Diaz said, according to ktvu.com, which obtained a copy of his safety alert. “We don’t have the tools to deal with a battery that is completely, basically destroyed.”

The nearest hydrant was roughly 2,000 feet away from Huang’s car and would have required a complete shut-down of U.S. 101 where the accident occurred, according to Mountain View Voice.

An EV battery’s high voltage is also a concern, Diaz said. Huang’s car was so badly damaged that the battery cut-off switch was destroyed. Autopilot had been engaged at the time of the wreck which is being closely reviewed by federal investigators.

Firefighters need to know where high voltage cables are located in an EV, Diaz said, prior to cutting through the vehicle to rescue its occupants.

Other fire department leaders share Diaz’ concerns in addressing EV accidents.

“If it’s a rescue, that’s where the real risk comes in cause I’m going to be cutting that vehicle, I want to make sure I’m not cutting through an electric cable,” said San Jose Fire Dept. Captain Mitch Matlow.

Diaz’ department called on Tesla for help in addressing the battery fire in Huang’s car. Tesla engineers, who work in nearby Palo Alto, responded and worked to stabilize the battery.

However, the battery continued to catch fire despite repeated efforts to extinguish it. Even six days after the crash, the battery reignited.

The battery was finally deenergized two weeks after the collision when Tesla and the NTSB worked together to deenergize it.

When it comes to responding to future EV accidents, Diaz instructed his fire crews to no longer touch the vehicle’s battery until it has been completely deenergized.

On its blog, Tesla, which has produced roughly 250,000 cars, defended its EV technology following the deadly Mountain View crash:

Tesla battery packs are designed so that in the rare circumstance a fire occurs, it spreads slowly so that occupants have plenty of time to get out of the car. According to witnesses, that appears to be what happened here as we understand there were no occupants still in the Model X by the time the fire could have presented a risk. Serious crashes like this can result in fire regardless of the type of car, and Tesla’s billions of miles of actual driving data shows that a gas car in the United States is five times more likely to experience a fire than a Tesla vehicle.