787 Problems Put Spotlight On Battery Technology
An electrical fire on a Boeing 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 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.
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, 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.