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NHTSA says it is too soon to recall vehicles or parts

As promised, the National Highway Traffic Safety Administration (NHTSA) looked into the safety of lithium batteries after a Chevrolet Volt caught fire back in May. After conducting three different tests two weeks ago, the NHTSA found that the Volt's battery either caught fire or began to smoke in two out of the three.

General Motors Co.'s Chevrolet Volt underwent several tests in a NHTSA Wisconsin facility earlier this year. On May 12, 2011, it experienced the side-impact crash test. Three weeks later, the plug-in electric vehicle (EV) caught fire while parked in the NHTSA testing center.

The fire, which was fierce enough to burn other vehicles parked nearby, prompted an investigation of the Chevrolet Volt and the safety of lithium batteries.

The NHTSA conducted side-impact crash tests for the Chevrolet Volt on November 16, 17 and 18. After each test, the batteries of the three separate Volts were then rotated 180 degrees. Out of the three tests, two resulted in fire, smoke or sparks while one remained normal.

The November 16 test had normal results, while the November 17 test led to a battery fire one week later and the November 18 test caused the battery to smoke and emit sparks. The battery packs of the three Volts were not drained after any of the crashes.

The results have led to a formal investigation of the safety of the Chevrolet Volt and its lithium battery.

"While it is too soon to tell whether the investigation will lead to a recall of any vehicles or parts, if NHTSA identifies an unreasonable risk to safety, the agency will take immediate action to notify consumers and ensure that GM communicates with current vehicle owners," said NHTSA.

GM has said that it launched a system where first responders immediately depower the battery of a Chevrolet Volt after a severe crash. This is safety protocol because lithium batteries can catch fire if the internal cells or the battery case are pierced by steel or another ferrous metal. Even the slightest piercing of the battery can lead to a reaction days or weeks later.

"The Volt is safe and does not present undue risk as part of normal operation or immediately after a severe crash," said GM after the NHTSA's tests this month. "GM and the agency's focus and research continue to be on battery performance, handling, storage and disposal after a crash or other significant event, like a fire, to better serve first- and secondary-responders."

NHTSA and GM have both said that they are unaware of any battery-related fires caused by roadway crashes involving customers. However, NHTSA advised EV owners to remain cautious in the event of a crash as they would in a gasoline or diesel-fueled vehicle. The NHTSA's advice includes stepping out of the car and moving away from it while contacting authorities. When responders arrive, they are to check for markings that it is an EV and use large amounts of water on the vehicle if there are any signs of a fire. They are to then contact experts at the vehicle's manufacturer on how to discharge a propulsion battery.

There are currently 6,000 Volt owners on the roads, but the number of EVs cruising around in the U.S. is expected to increase because U.S. President Barack Obama is looking to put 1 million EVs on the roads by 2015.

Sources: The National Highway Traffic Safety Administration, General Motors

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By dew111 on 11/28/2011 5:25:48 PM , Rating: 4
"When responders arrive, they are to check for markings that it is an EV and use large amounts of water on the vehicle if there are any signs of a fire."


That is all.

RE: Uhhhh...NO!
By FirNaTine on 11/29/2011 12:55:48 AM , Rating: 3
Realize there is a tipping point where sufficient water will provide cooling that exceeds heat released from the reaction.

Telling a firefighter to apply copious amounts of water (from the actual bulletin) is a reflection of this, and would be in the thousand to several thousand liter per minute application rate range.

RE: Uhhhh...NO!
By relztes on 11/29/2011 12:38:49 PM , Rating: 2
The main fire risk in a lithium battery is actually the organic electrolyte, which is flammable. Electrochemical reactions may initiate the fire, but once it gets going, it's mostly the electrolyte that burns. Since the electrolyte is miscible with water, this should work. The combustion energy of the electrolyte is much greater than the energy stored in the battery. This is actually why lithium ion batteries have a greater fire risk than other battery chemistries, which use water based electrolytes.

RE: Uhhhh...NO!
By EddyKilowatt on 11/29/2011 8:11:09 PM , Rating: 2
There's no lithium metal in a lithium-ion battery. Just lithium compounds, that don't act so much like alkalai metals.

As already noted, what burns is the organic solvent electrolyte, followed by the anode and cathode materials.

The number one thing in fighting a fire in a large lithium-ion pack is to keep the fire from propagating from one or a few cells, to a few hundred or few thousand cells. The way you do that is exactly what the article said... lots of water. Not to put out the fire per se, but to cool things off and keep adjacent cells from getting hot enough to 'cook off'.

There are some FAA training videos out on the web somewhere about dealing with laptop battery fires, that say basically the same thing. Water, lots of it, try to get things cooled off.

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