From Boeing land..
Battery maker GS Yuasa believes the fix for the battery should include a voltage regulator that could stop electricity from entering the battery, the Journal said.
Boeing proposed its fix to the FAA on Friday, but on Thursday, Yuasa told the FAA that its laboratory tests indicated that a power surge outside the battery, or other external problem, started the failures on two batteries, according to the newspaper.
Boeing, battery maker at odds over 787 fix - WSJ | Reuters