HONG KONG (BLOOMBERG) - Runaway raw material costs are fueling a "ridiculous" increase in the price of batteries for electric vehicles (EVs), according to Li Auto chief executive Li Xiang, who took to social media in China over the weekend to offer a rare insight into EV makers' pain.

"The cost of batteries in the second quarter rose by a very ridiculous amount," Mr Li said on his official Weibo account late on Saturday (March 19). Carmakers that have not raised prices yet are probably going to have to once their battery suppliers start charging more, he added.

Mr Li's comments came after automakers in China from Tesla to BYD increased the prices of their cars. Xpeng also hiked costs last week, saying in a note to customers that it will increase the price of its EVs by between 10,100 yuan (S$2,150) and 20,000 yuan.

Car manufacturers in China, the world's biggest EV market, are trying to lure more customers just as government subsidies for cleaner vehicles fall away. Combustion engine cars, still made by the likes of BYD and Geely Automobile Holdings, are also facing higher running costs due to soaring oil prices.

Contemporary Amperex Technology Co (CATL), the world's largest battery maker, has noted the higher commodity costs, saying they are applying pressure on cell and automakers alike.

"The surge of upstream raw materials has caused certain pressure on downstream segments of the industry chain including carmakers and battery makers," a CATL spokesman said. "We adhere to the principle of providing customers with high-quality products while maintaining a reasonable level of profit."

Smaller EV maker WM Motor Technology also cited raw materials prices and supplier constraints for its increases of between 7,000 yuan to 26,000 yuan after subsidies, according to a Weibo post last week. Those hikes kick in from March 28.

Li Auto gets its batteries from CATL, as does WM Motor, among other suppliers, according to Bloomberg Intelligence.