Its A350, built to compete with the 787, also uses lithium-ion batteries and is scheduled for test flights this year.

FORBES: The Dreamliner: Boeing's Big Brand Hangs in the Balance

So right now we're looking to move from lead-acid to lithium-ion batteries and we're working with the US Navy on a test programme that would allow us to do that.

BBC: US manned deep-submersible Alvin prepares to resume work

The Federal Aviation Administration has prohibited commercial, test and delivery flights of U.S.-registered 787s since twin lithium-ion battery incidents on Japan Airlines Co.

WSJ: Air India Flew Boeing 787s After 'Grounding'