From BBC news
"....Boeing has backed the battery used in the Dreamliner after Japan Airlines and All Nippon Airways said they changed a number of them in the past few months.........Boeing said while the replacement rate was "slightly higher" than usual, the changes were "routine maintenance" ......
On Wednesday, All Nippon Airways said it replaced batteries 10 times over the past few months, while Japan Airlines said it did so in a "few cases" over the past few months. Boeing said that it was carrying out an investigation to find out what caused the battery malfunctions.
.....said Mr McNerney, chief executive of Boeing.
"We feel good about the battery technology and it's fit for the aeroplane"..... "
BBC News - Dreamliner: Boeing defends 787 batteries
I wonder why "routine maintenance" has led to "an investigation". And if McNerney and the management team "feel good" about the battery arrangement, I wonder how the Boeing stockholders feel about the management team.