(UPDATED with information on control circuit, below the photos.)
From Yomiuri Shinbun (1/18/2013):
Reuters reports (1/17/2013) that the control circuits for the batteries in Boeing 787 are made by a French company Thales SA, and they are part of a power unit supplied by a US company UTC Aerospace, part of United Technologies Corp:
- Boeing's new 787 airliner uses two lithium-ion batteries made by the Japanese company GS Yuasa Corp (6674.T), with the associated control circuits made by Thales SA (TCFP.PA). They are part of an auxiliary power unit supplied by UTC Aerospace, a unit of United Technologies Corp (UTX.N), that provides power while the airplane is on the ground.
- Lithium-ion batteries can catch fire if they are overcharged, and once alight they are difficult to extinguish because the chemicals produce oxygen. But Boeing said it designed multiple systems to prevent overcharging, contain a battery fire and siphon smoke away before it reaches the cabin.
- Boeing said the battery it uses on the 787 is about twice as large as a car battery and has been extensively tested, both in the lab and in operation. The U.S. National Transportation Safety Board said the auxiliary power unit battery that caught fire on January 7 at Boston's Logan International Airport weighed about 63 pounds and measured 19 inches by 13 inches by 10.2 inches.
There is a speculation (not yet proven) that the controller was built on one of a bad circuit board batch produced in Mexico in both JAL and ANA planes.
(H/T reader netudiant)