Major Japanese automotive and industrial battery-maker GS Yuasa International Ltd. will boost car battery production in Thailand to serve demand stemming from growing vehicle sales in Southeast Asia.

Siam GS Battery Co., the Kyoto-based company's Thai joint venture, plans to invest 1 billion baht ($30 million) to increase annual output capacity by 25 percent to 5 million units by the end of 2020, as well as to expand its overseas business, said Prakasit Phornprapha, executive director of the local unit.

The Thai unit, in which the Japanese company owns a 60 percent stake, holds a 40 percent share in the domestic replacement car battery market, followed by other Japanese brands Hitachi Chemical Co. at 19 percent and Furukawa Battery Co. at 18 percent, according to German research firm GfK's data cited by Prakasit at a recent news conference in Bangkok.