New Boeing 787 Battery Problems in Japan

A sensor problem was found Sunday in one of the exchanged batteries for a Japan Airlines Boeing 787 jet but did not pose a safety risk, a Japanese broadcaster reported.

The Boeing Co. jets had been grounded for four months until their safety could be reconfirmed. The problem emerged in a sensor that detects overheating in the modified version of the lithium-ion batteries used in the aircraft, NHK TV said.

The batteries were encased to prevent overheating from spreading in a redesign of the aircraft's power system in Feburary, according to Boeing.

Earlier problems with the "Dreamliner" batteries overheated on planes that were in flight in Japan and parked in a Boston airport. The jets resumed commercial flights last month at JAL and All Nippon Airways.