According to this report there was a history of battery issues with ANA 787s.
http://www.nytimes.com/2013/01/30/bu...anted=all&_r=0
The airline said it told Boeing of the replacements as they occurred but was not required to report them to safety regulators because they were not considered a safety issue and no flights were canceled or delayed.
As 5 of the 10 batteries replaced were changed because they had become discharged, maybe this should now be considered a safety issue, as charging from a low state of charge seems to be as risky as overcharging. If the regulators had been given a heads up about the number of battery replacements ANA had carried out, would things have been different?
And did any of the other 787 operators experience similar problems and how much did Boeing know about this?