TOKYO, April 24 Mitsubishi Motors Corp said the overheating of lithium-ion batteries used in its Outlander SUV plug-in hybrid was likely to have been caused by cells that were damaged when dropped onto the ground during manufacturing.
The company stopped production and shipments of the model in late March after it found a lithium-ion battery had overheated in one of the vehicles.
Mitsubishi Motors said on Wednesday it will announce recalls of all 4,305 of the Outlander plug-in hybrids it has sold since the vehicle went on sale in January, as well as 115 electric vehicles including the i-MiEV, once it decides how to prevent the manufacturing error.
The plug-in hybrid is sold only in Japan.
Batteries in the Outlander plug-in hybrids are supplied by a joint venture called Lithium Energy Japan, owned by GS Yuasa Corp, Mitsubishi Corp and Mitsubishi Motors. Kyoto-based GS Yuasa is also the battery maker for Boeing Co's 787 Dreamliner jets.
Mitsubishi believes plant workers may have dropped some cells on the ground, damaging them. Those cells should have been removed from the production line, but some were likely to have been used in batteries, it said. Tests found that when those batteries were charged they overheated.
"It is not a problem in the batteries themselves," said Ryugo Nakao, managing director of Mitsubishi Motors, adding that the company wants to resume production of the vehicles in May.
Separately, Mitsubishi said on Tuesday it is recalling 3,839 Outlander plug-in hybrids due to a problem in the software that controls the front and rear drive motors, as well as potential problems in the vehicle's generator and front drive motor.
It is set to release its fourth quarter results on Thursday.