Mitsubishi Motors says a battery in a plug-in hybrid Outlander vehicle heated up and melted. No one was injured.
Separately, the Japanese automaker said Wednesday a battery for i-MiEV electric cars caught fire at an auto-assembly plant, but that no one was injured.
Mitsubishi Motors Corp. said the problems with the lithium-ion battery occurred during production, and may be related to a change in production methods in December.
Spokesman Kai Inada said the company was investigating the cause and has not issued any recalls related to the problem.
Mitsubishi has received orders for 7,500 Outlander vehicles and delivered 4,000, all in Japan.
Both batteries were made by GS Yuasa, the Japanese supplier for Boeing Co. 787 jets, which has also had battery overheating problems.
Inada said the products are different.