So that's for JAL's battery. No word yet on ANA's. There is no mention of multiple occasions of JAL and ANA exchanging batteries throughout last year.
From ABC News (2/7/2013):
The battery fire that grounded Boeing's Dreamliner back in January was started in one of eight battery cells that make up the lithium-ion battery used to power the plane when all other power sources fail, NTSB investigators said at a news conference today.
The single cell showed signs of short circuiting that led to thermal runaway -- a chemical reaction during which a rising temperature leads to increasingly higher temperatures, and spread to the rest of the battery, the board reported.
The NTSB has ruled out external short circuiting as a cause for the problems.
"Boeing has indicated that these tests that were conducted prior to certification showed no evidence of cell-to-cell propagation or fire in the battery," Deborah Hersman, chairwoman of the NTSB, said today in Washington. "However, our investigative findings with respect to the event battery show that when a short circuit did occur, it resulted in cell-to-cell propagation in a cascading manner and a fire."
...The certification tests by Boeing found that the likelihood of "smoke emission" from one cell and then a spread to other areas would occur in less than one out of every 10-million flight hours. The 787 currently has only 100 thousand flight hours, and already there have been two smoke events -- one resulting in a fire.
...But the NTSB said Boeing failed to mitigate the hazards and must review not only the battery problem but its testing that provided false conclusions.
(Full article at the link)
It looks like both Boeing and GS Yuasa have some explaining to do, but to say the "testing ... provided false conclusions" is a bit harsh. As Boeing says, in the article:
"We provided testing and analysis in support of the requirements of the FAA special conditions associated with the use of lithium ion batteries..."
In other words, Boeing provided exactly what the regulator wanted.