Boeing has provided additional details on the battery fix:
Boeing Releases More Details on Dreamliner Battery Fix
Boeing released additional details about its plans to revise the design of the trouble-prone lithium-ion batteries that caused two fires that resulted in the worldwide grounding of the Dreamliner fleet.
The changes and improvements will add several layers of safety and could be ready to be deployed to the fleet, pending FAA approval, in a matter of weeks.....