Following the meltdown of two lithium-ion battery packs in Japan – one at a dealer, the other at an assembly plant – Mitsubishi has halted Japanese production and sales of its Outlander plug-in hybrid.

The decision affects only Japan at this stage, as the company tries to determine whether a fault could affect the i-MiEV sold in the U.S, but it in fact has yet to determine the exact cause.

“We announced this issue before a recall to tell the consumers immediately for their safety,” said Mitsubishi spokeswoman Namie Koketsu in an interview with Automotive News. “We’re still trying to determine which cars are affected and the root cause.”

One meltdown incident in which an actual fire resulted occurred March 18 when a pack at Mitsubishi’s Mizushima assembly plant. The battery in an inspection room started smoking and an hour later it caught fire, according to reports.

Mitsubishi is in the meantime advising owners of the Outlander plug-in to not recharge their vehicles.

As for its U.S. launch expected some time next year, the vehicle has been anticipated for the past few years, and Mitsubishi has said it does not expect the problem to delay its American release.

To date, Mitsubishi has sold 4,000 of them in its home country after beginning sales January 24 and this has been quite the achievement given that only 2,500 units of the regular gas-powered Outlander sold since an October 2012 launch.

Mitsubishi’s batteries were made by Lithium Energy Japan which is a joint venture with GS Yuasa Corp.

GS Yuasa also made the batteries that grounded the Boeing 787 Dreamliner.

Although not proven yet, Mitsubishi is suspecting the issue can be traced to a defect in manufacturing.

Batteries also supplied by Toshiba, and equipped in lower trim level i vehicles, are believed to be OK.

Automotive News