The Japanese government has ended its investigation of a January 2013 battery incident aboard a Boeing Co 787 Dreamliner jet without specifying the cause of the battery's overheating, the Japan Transport Safety Board said on its website. The Boeing aircraft operated by ANA Holdings Inc was forced to make an emergency landing in western Japan due to the battery glitch, which followed another battery-related incident less than two weeks earlier in Boston and prompted authorities to ground the global fleet of Dreamliners for more than three months. (Reuters)