Battery maker GS Yuasa Corp 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 agency that its laboratory tests indicated a power surge outside the battery, or other external problem, started the failures on two batteries, according to the newspaper.
The FAA confirmed the meeting with Yuasa, but did not give any details.
A Yuasa spokesman declined to comment. Boeing spokesman Marc Birtel said that the investigation has not showed that overcharging was a factor and that the 787 had quadruple-redundant protection against overcharging in any case.
"Our proposal includes multiple layers of protection covering the known potential probable causes of the events," Birtel said by email.
He did not respond directly to the comments about Yuasa, although he added that Boeing was coordinating with key suppliers.
No comment was immediately available from Securaplane, the company that makes the charger for the battery.