LG Chem Ltd., the world’s largest lithium-ion battery maker, said Wednesday that it has signed a deal with Japan’s second-largest mobile carrier to provide batteries starting this month.

LG Chem said the batteries will be used as uninterrupted power supply, or UPS, in 130,000 base stations of Softbank Mobile Corp. The UPS is an electrical apparatus that provides emergency power to base stations when the input power fails.

The total electricity of the batteries to be provided to the Japanese mobile carrier reaches about 20 megawatt-hours, LG Chem said. A megawatt-hour is equal to 1 million watts being used continuously for an hour.

LG Chem hopes to provide additional lithium-ion batteries to other Japanese mobile carriers, including NTT Docomo Inc., as they reportedly plan to change batteries in their UPS units to lithium-ion ones from lead-acid ones.

The UPS market in Japan is estimated at about 900 billion won ($804 million), while its global market is estimated at approximately 8 trillion won, the company said. (Yonhap News)