Boeing Co and the Japanese company that makes lithium-ion batteries for Boeing's 787 Dreamliner disagree about what should be included in a package of measures aimed at getting the airliner back in the air, the Wall Street Journal reported on Wednesday, citing government and industry officials.

Battery maker GS Yuasa <6674.T> 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.

A Yuasa spokesman was not immediately available for 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.

The FAA did not have an immediate comment, and no comment was immediately available from Securaplane, the company that makes the charger for the battery.

(Reporting By Jim Wolf, Andrea Shalal-Esa and Peter Henderson; Editing by M.D. Golan)