Japan to Investigate Boeing 787 Battery Maker

GS Yuasa Corp.'s logo is displayed outside the company's office in Tokyo, Japan.
Junko Kimura | Bloomberg | Getty Images
GS Yuasa Corp.'s logo is displayed outside the company's office in Tokyo, Japan.

Japan's transport ministry is to investigate the company that makes batteries for Boeing's grounded 787 Dreamliner passenger jet. The probe will be run jointly with the U.S. Federal Aviation Administration (FAA), a ministry official said on Monday.

Authorities around the world last week grounded the new lightweight aircraft, and Boeing halted deliveries after a problem with a lithium-ion battery prompted an All Nippon Airways 787 to make an emergency landing at Takamatsu airport during a domestic flight. Earlier this month, a similar battery caught fire in a Japan Airlines' 787 parked at Boston Logan International Airport.

(Read More: US Experts Arrive in Japan to Assist Probe of ANA Dreamliner)

U.S. safety investigators on Sunday ruled out excess voltage as the cause of the Boston battery fire on Jan. 7, and said they were expanding their probe to look at the battery's charger and the jet's auxiliary power unit.

"Results have shown the battery was abnormal in both the Boston and Takamatsu (incidents). They were the most damaged," Shigeru Takano, a senior safety official at Japan's Civil Aviation Bureau, told reporters. "We will look into if the work that took place, from design to manufacturing, was appropriate." He did not name the battery maker.

(Read More: Japan Airlines' Grounded Boeing Dreamliner Leaks Fuel in Tests)

A spokesperson for Kyoto-based GS Yuasa, which makes batteries for the Dreamliner, declined to comment. Shares in the firm, valued at close to $1.5 billion, slipped 1 percent on Monday, and have dropped 11 percent since the Boston fire. The benchmark Nikkei was down 0.9 percent.

The grounding of the Dreamliner, an advanced carbon-composite plane with a list price of $207 million, has forced ANA to cancel 141 flights between Wednesday and Sunday, affecting more than 18,000 passengers, the carrier said on Monday. Those cancellations added to the 72 flights scheduled for Jan. 19-22 that ANA called off last week.

(Read More: Being Closer to an Answer, but Not to Getting 787s Back in the Air)

Japan is the biggest market to date for the Dreamliner, with JAL and ANA flying 24 of the 50 passenger jets that Boeing has delivered.