NFPA Journal - January/February 2020 - 36

in the NFPA course on EV and battery response. Based on fire testing
conducted at the request of the Fire
Protection Research Foundation
(FPRF), NFPA recommends that firefighters shoot "copious amounts of
water" directly on the area of the battery case, and use a thermal imaging
camera to periodically look for signs

36 | NFPA JOURNAL * J A N U A R Y / F E B R U A R Y 2 0 2 0

of heat from the ongoing chemical
reaction inside the battery. However,
because EV batteries are typically
tucked between the vehicle's undercarriage and passenger compartment,
firefighters say it can be hard, if not
impossible, to access the battery to get
water on it. The inclination for some
is to try and cut holes in the vehicle

COURTESY OF CENTRAL AND WEST BRABANT FIRE BRIGADE

p With no established way to safely transport damaged EVs, firefighters have had to get
creative. In the Netherlands, departments have begun transporting damaged EVs inside
containers filled with water to neutralize the reignition threat. Above, crews load a BMW
EV into a water bath after the battery began smoking inside a car dealership last spring.

floor to expose the battery, said Cory
Wilson, a battalion chief at the Fremont
(California) Fire Department, who for
several years has led trainings on emergency response in Tesla vehicles. That
strategy is dangerous and counterproductive, he said.
"The Tesla battery is separated into
15 different compartments, so if you
start poking holes from one compartment into another, you're going to
spread that fire quicker and further
and you could actually cause damage
and begin the thermal runaway process
in more of those cells," he said. Also, "if
you cut into the high-voltage lines, you
will be dead instantly."
In Fremont, home to Tesla's 10-million-square-foot production plant, the
fire department has started using a
special form of jack during EV fires to
lift the vehicle up on its side, allowing
firefighters to lob water at the undercarriage close to the battery. "We also
fill up the floor pan of the vehicle itself
to keep the battery cool from the top
side," he said. "Still, you're not necessarily getting water directly on the battery
itself. You're cooling the elements
around it."
Another potential option for stopping thermal runaway is to drain the
battery of the energy causing the reaction, which is much easier said than
done, according to Victoria Hutchison,
a research project manager at the
FPRF. The typical de-energization
method used by many manufacturers
is to submerge the damaged battery for
several days in a salt water bath until
the bubbles stop, indicating that the
chemical reaction inside the battery
has ceased. While this tactic may seem
less than ideal for first responders on a
freeway who lack the technical expertise to remove a damaged battery, the
lack of tried and tested options has
forced them to get creative.
In the Netherlands, firefighters use
tow trucks to transport large shipping
containers to the site of EV accidents
where a battery has been compromised. The box is filled with water,
and a small crane lifts the vehicle and
lowers it into the bath, where it can be
safely taken away to an impound. This
strategy is becoming more common
NFPA Journal - January/February 2020

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