TB 172 - Electric & Hybrid Vehicles And Lithium-Ion Battery Safety Flashcards
A Lithium-ion battery is subject to thermal runaway when it has been damaged from either penetration or crushing in a collision, exposed to heat, or internal short circuit due to a factory defect or aging.
What is “Thermal Runaway”?
When a battery cell suffers a SHORT CIRCUIT; the battery heats up and continues to produce heat, even when it is extinguished and/or submerged in water.
During a thermal runaway event, temperatures can exceed over ______ degrees Fahrenheit. The battery cell itself will suffer a self-destruction of its structure (these are small explosions and “pop” noises Firefighters may hear) and the gases and heat produced will cause the module casing to vent (these are the “thump” noises Firefighters may hear on the scene as the modules’ pressure caps open up).
900 degrees
Fires have occurred in several EV vehicles in the United States and the world primarily due to?
high-speed impacts.
After any traffic collision involving an EV or Hybrid vehicle, no personnel shall come in contact with any of the batteries or its components until it is verified that it is _________.
de-energized.
EV/Hybrid Vehicle Challenges for the LAFD:
- Exposed EV batteries, including wiring and components, can kill anyone that comes in contact with it.
- LAFD is not equipped to fully disassemble and disable Lithium-ion batteries. Fire will burn for hours if batteries are damaged.
- On-scene time is greater due to THERMAL RUNAWAY
- No equipment or tools that can identify any Direct Current (DC). Hot Stick is only for AC
EV Collision or Fire:
To ensure there is no potential for transmission of electricity, LAFD personnel shall establish a ______ ft safety zone when extinguishing an EV fire with water and wear full structure fire PPE and SCBA.
Always consider the vehicle as energized.
30 ft
True or False?
NFPA has conducted research on vehicle fires involving EV. Results have shown that even when the EV battery was on fire, NO ELECTRICITY was transmitted through the water stream and nozzle back to the Firefighters.
True.
Even still, maintain 30ft safety zone and use all PPE’s
EV Collision or Fire:
Use of the _________ can be used to facilitate the status of a battery’s internal thermal runaway and determine if temperatures are going up or down.
-thermal imager camera
(could take 2,600 and up to 3,000 gallons of water to effectively cool down the battery.)
EV Collision or Fire:
If the battery is still intact after a vehicle fire/accident it will be nearly impossible to penetrate all of the modules and cells with water. Thus, expect re-ignition of the battery to occur for several days.
One option to ensure penetration into the battery is to?
completely submerge the battery in water.
EV Collision or Fire:
LAFD personnel working on vehicles after a fire or accident SHOULD wear ________ any time they come in contact with the vehicle, including incidents that require extrication.
Gauntlet Gloves
EV Collision or Fire:
LAFD personnel shall make every attempt to disconnect the DC electrical battery at the vehicle’s “___________.”
First Responder Loop
(Consult with the vehicle manufacturer for the location of the first responder loop and DOUBLE CUT the wiring to ensure they will not touch.)
True or False?
The use of foam can be COUNTERPRODUCTIVE with Lithium-ion batteries.
True.
(a layer of foam can actually insulate the hot area to prevent further cooling)
EV Fire:
To conserve water and have a MORE EFFECTIVE COOLING, LAFD personnel will use a _______ rather than a high-pressure straight stream.
-Low flow fog
(Low flow is considered nozzle pressure under 50 psi)
(Consideration should be given to ordering a Water Tender on Freeway incidents where a water supply cannot be established. Extinguishment will take thousands of gallons of water)
_________ coming from the high-voltage battery are signs of a potentially overheating battery (thermal runaway) which could result in a DELAYED FIRE.
Sparks
Smoke
Bubbling noises
True or False?
According to NFPA, the use of water DOES NOT present an electrical hazard to firefighting personnel.
True.
