@Lyman
Also, once discharged, these batteries cannot be "recharged" according to Boeing...and Yuasa.
They cannot be recharged aboard the airplane. They can be recharged on the bench. This information comes from 787 Electrical Engineers with direct knowledge of the procedures.
Were the accident batteries in the "replacement group"?
JA829J's would not have been as the airframe had just been delivered, so it had the APU battery installed at the factory.
JA804A did have it's Ship's Battery replaced in October 2012, but as to whether it was a reconditioned battery, I cannot say.
Can you cite a source?
At least 100 batteries failed on 787 fleet | Business & Technology | The Seattle Times
Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated.
The person on the 787 program with knowledge of the problems said that the electrical-system design makes it commonplace for airline mechanics to inadvertently run the lithium-ion batteries down too low.
Because lithium-ion batteries can be dangerously volatile if undercharged, as well as when overcharged, an automatic cutoff is built into the 787 batteries so that if the charge falls below 15 percent of full, the battery locks.