US and Japanese authorities have begun a joint probe into the Japanese battery maker for Boeing’s 787 Dreamliner aircraft.
It comes after an All Nippon Airways 787 had to make an emergency landing due to a battery malfunction.
However, US National Transportation Safety Board (NTSB) said the battery did not overcharge in a separate incident when an electrical fire broke out on a Japan Airlines 787 at Logan International Airport in Boston.
The NTSB said it would now widen its probe to look at the battery charger and the auxiliary power unit.
ANA and JAL have both extended their 787 flight cancellations to January 28.
ANA, which was the 787 launch customer and operates 17 Dreamliners, said the total number of 787 flights it has been forced to cancel since the January 16 incident now stands at 320 domestic and 51 international, with more than 50,000 passengers affected.
Flights of all 50 787s operated by eight carriers worldwide have been suspended.
Boeing has also suspended deliveries of the aircraft pending the outcome of safety investigations.
