Hyundai and its main battery supplier have begun an investigation into reports of fires, leading to a recall of over 25,000 cars.

Reuters reports that the recall, which includes software updates and battery replacements after inspections, involves 25,564 Kona electric vehicles (EVs) built between September 2017 and March 2020, the South Korean transport ministry said in a statement.

The safety recall "is a proactive response to a suspected defective production of high-voltage batteries used in the vehicles, which may have contributed to the reported fires", Hyundai said, adding that it will deploy all necessary measures to identify the cause of the fire and address customers' needs.

The Reuters report says some 13 incidents of fire involving the Kona EV, including one each in Canada and Austria, have been documented, according to the office of ruling party lawmaker Jang Kyung-tae. 

Kona EVs use batteries made by LG Chem Ltd.

LG Chem said the exact cause of the fire had not been determined and a reenactment experiment conducted jointly with Hyundai had not led to a fire, so the fires could not be attributed to faulty battery cells.

It would actively participate in future investigation with Hyundai to find the cause, LG Chem added in a statement.

Hyundai's shares fell 1.4%, reflecting investor concern that the recall and battery replacements could be costly, as the battery accounts for about 30% of an EV’s price, analysts said.

In contrast, LG Chem shares rose 1.8%.

The Kona Electric is the South Korean automaker’s first long-range subcompact SUV EV.  The affected cars were manufactured in Korea up to this year. Hyundai now also makes the car at its European plant in the Czech Republic.

In July, Hyundai Motor Group leader Euisun Chung said Hyundai Motor and sister company Kia Motors aim to sell 1 million battery-driven electric vehicles in 2025, targeting more than 10% of the global market share for such vehicles.