* Battery technology part of weight-reducing design of 787
* Boeing says overcharging can lead to battery fire
* Boeing designed 787 to prevent overcharging, contain fires
* Plane maker says battery was the correct choice
By Deepa Seetharaman and Alwyn Scott
DETROIT/NEW YORK, Jan 9 (Reuters) – An electrical fire on
Boeing’s new 787 Dreamliner is drawing renewed scrutiny
for lithium-ion batteries, an increasingly important component
in planes and hybrid cars.
A Japan Airlines 787 experienced a battery fire
while parked on the ground in Boston on Monday, causing
substantial damage in an equipment bay. While the plane is
designed to contain the smoke from such a fire in-flight,
because it was on the ground the smoke entered the cabin.
The use of the new battery technology is among the
cost-saving features of the 787, which Boeing says burns 20
percent less fuel than rival jets using older technology.
Boeing used electrical systems extensively on the 787
instead of traditional hydraulic equipment – a change that
reduced the 787’s weight but added to its complexity.
Lithium-ion batteries can catch fire if they are
overcharged, and once alight, they are difficult to extinguish
because the chemicals produce oxygen, Boeing’s chief engineer
for the 787, Mike Sinnett, said on a conference call with
reporters Wednesday.
Engineers designed multiple onboard systems to prevent
overcharging, contain a battery fire and siphon smoke away
before it reaches the cabin, Sinnett said.
He said a lithium-ion battery was not the only choice of
battery, but “it was the right choice” and “knowing what I know
now, I’d make the same choice now.”
Sinnett wouldn’t discuss specifics of the Japan Airlines
fire, which is being investigated by the National Transportation
Safety Board, and it wasn’t known whether there was a fault with
the battery, which was made by GS Yuasa Corp, which has
said it is investigating. Sinnett said Boeing is
not considering using different battery technology.
The battery that caught fire was part of an auxiliary power
unit designed to provide electricity when the plane is on the
ground. The battery is about twice as large as a car battery and
it has been extensively tested, both in the lab and in
operation. “We’ve got 1.3 million operating hours on these
battery cells in flight with no issues,” Sinnett said.
TEST AND RE-TEST
A similar challenge confronts automakers and other users
over lithium ion batteries, which are used in laptops and other
electronics.
“It is always difficult to predict the level of safety
precaution needed for new technology,” said Menahem Anderman, a
battery consultant who worked on the Boeing 777 battery systems
when he was at Acme Electric Corp, in an email.
“One of the challenging design criteria that automakers are
struggling with is whether it is necessary to ensure that if a
single cell catches fire, the fire does not propagate to other
cells,” he said.
While Dreamliner passengers may not realize there is a
lithium-ion battery inside the plane, drivers of electric cars
do. The auto industry has been increasingly veering toward using
lithium-ion batteries rather than the cheaper, but heavier
nickel-metal hydride battery used by Toyota Motor Corp
in its top-selling Prius.
General Motors Co, the largest U.S. automaker, uses a
lithium-ion battery in its Chevrolet Volt plug-in hybrid, while
its smaller U.S. rival Ford Motor Co uses the technology
in its green cars, including the recently launched C-Max hybrid.
The technology is favored in the latest generation of such
cars for the same reason plane makers are keen to use it — the
batteries can be made lighter, smaller and in a way that retains
capacity longer. Lithium-ion batteries are about half the weight
of nickel-metal hydride batteries.
In 2011, a lithium-ion battery pack in a Volt caught fire
three weeks after a U.S. safety regulators conducted a crash
test. But after a two-month investigation, the National Highway
Traffic Safety Administration determined that the Volt and other
electric vehicles posed no greater risk for a fire than
gasoline-powered vehicles.
Lithium-ion battery maker A123 Systems was forced to recall
battery packs made for Fisker Automotive’s plug-in hybrid sports
car, the Karma, last year. A123, which ultimately went bankrupt,
citing a manufacturing defect for the problems in the batteries.
“Because they’re new and different, a fire in an electric
car gets a lot more attention than in a gas car,” said Tom Gage,
a battery expert whose company EV Grid works on ways to manage
the charging of electric cars. “The standard is, are they as
safe as the gas tank? That’s certainly the target they have to
strive for.”
He said there probably wasn’t enough data to determine
their comparable safety record.
GM is exploiting the technology aggressively in the Volt,
having done 100 million miles of drive testing by the CEO’s
account. Chief Executive Dan Akerson said Wednesday that GM
tests the batteries “like you wouldn’t believe” and was
confident in its safety procedures. He declined to comment on
Boeing’s battery use.
(Reporting by Deepa Seetharaman; Additional reporting by Ben
Klayman; Writing by Ben Berkowitz; Editing by Lisa Shumaker)
