CAMPBELL (KPIX 5) – The day after a Tesla Model S vehicle burst into flames not once but twice, Santa Clara County fire officials on Wednesday admitted that they are still learning how to handle fires involving the electric vehicles.
The car’s battery pack caught fire twice on Tuesday, leaving the Tesla a charred and smoldering mess.
The first fire happened at around 2 p.m. Tuesday after the owner, who didn’t want to be identified, was coming down Highway 17 and got a low tire pressure warning.
The vehicle was towed to a tire repair shop on University Avenue in Los Gatos. The owner was inside the shop doing paperwork when he heard hissing. He approached the car and saw smoke before taking out his cell phone and shooting video of the car as flames shot out from underneath the front of the vehicle.
“If this car had been in my house today and we go on vacation or something and the car suddenly catches fire the whole house can burn down, right? So I’m certainly worried,” said the owner. “My wife doesn’t want me to own another Tesla.”
Santa Clara Fire crews arrived to find the front end of the car engulfed in flames. The fire was quickly put out without spreading or causing any damage to the building.
“The vehicle started off-gassing, making a loud hissing noise and producing some additional smoke,” said Santa Clara County Fire Captain Bill Murphy. “That’s an indication that there’s some type of combustion process happening in the batteries.”
Crews planned to remain on scene to make sure the vehicle cools and is safe to tow to a different location to continue the investigation into the cause of the fire. There were no injuries to firefighters or bystanders.
While KPIX 5 has reported on other instances of Teslas catching on fire after accidents, officials are still uncertain how and why this car fire started.
The Santa Clara County Fire Department told KPIX 5 this is a pretty rare occurrence. In fact, Tuesday’s incident was the very first Tesla battery fire the department has ever had to deal with.
The car re-ignited at around 10:30 p.m. Tuesday night as it was being moved to a tow yard in Campbell.
Firefighters sprayed several thousand gallons of water trying to douse the stubborn flames coming from the battery pack of the Tesla Model S.
In a typical gas-powered car, the fire would’ve been relatively easy to douse no time, but it took crews more than half an hour to extinguish the Tesla a second time.
Part of the issue with Tesla fires is getting to the batteries, which is difficult because the vehicles are so low to the ground. The packs are also covered by a thick metal plate to protect the batteries from being punctured.
Crews used a forklift to raise up the car and prop it up on some wooden blocks and spray water directly onto where the battery pack ignited.
“We’re going to access it the best we can, but at the same time we’re not going to be tearing into the batteries,” explained Murphy.
Santa Clara County Fire officials said they followed Tesla’s protocol to cool the battery pack with water, then observe it for heat and flames before to trying to move it.
After six hours of waiting while talking with Tesla technicians on the phone, it was the fire department that made the final call to move the car to the tow yard.
When asked if dealing with Tesla fires was still kind of a learning process, Captain Murphy replied, “Yeah, absolutely. Again, the batteries actually burning as we are seeing presents a challenge that we need to become more familiar with. And again, we’ve been able to work with Tesla and we will continue to do it.”
Tesla says its cars are designed with firewalls to prevent flames spreading from battery modules into the passenger compartment.
But experts say the same design that slows spread of fire — allowing driver and passengers time to get out — also slows the fire fight.
“The heat and the fire is actually inside the cells inside the batteries, so it’s very hard to get the water and the cooling to that,” explained Gerbrand Ceder, a scientist at Lawrence Berkeley National Laboratory.
Unlike a regular fire, Ceder tells KPIX 5 it’s chemicals inside the batteries that are producing the heat in these cases.
“There are firewalls to stop the heat from spreading, and that’s important because of one cell catches fire, you don’t want it to infect the other cells,” said Ceder. “But unless you can bring the temperature down, it could slowly heat up again. And that’s why you get these spontaneous re-ignitions.”
The company also says that their cars catch fire about ten times less frequently than gas-powered cars. Tesla has been providing training to first responders and is expanding those efforts.
As to what caused the two fires with the vehicle, Tesla says the cause is still under investigation.