Kyodo News, quoting firefighters and authorities, said the Tokyo-bound "Dreamliner" jet landed at Takamatsu airport at about 8:45 a.m. shortly after taking off from Yamaguchi Ube airport in western Japan.
Authorities said the aircraft's meter in the cockpit showed battery problems and that one of the pilots smelled an abnormal odor, Kyodo reported.
The BBC reported local television channels showed the plane's emergency chutes being deployed and quoted the airline as saying fire truck were on the runway as the plane landed.
Boeing spokesman Paul Lewis told the BBC the company was aware of the diversion of the plane to Takamatsu and "will be working with our customer and the appropriate regulatory agencies."
The emergency landing is the latest incident involving the new plane. Among other incidents involving other Boeing 787s, there were reports of two fuel leaks, a wiring problem, a brake computer glitch and a cracked cockpit window, the BBC said.