SHANGHAI (Reuters) – China’s top electric vehicle battery maker CATL <300750.SZ> said on Monday it has signed a battery supply agreement with Tesla <TSLA.O>.

Tesla will determine the battery purchase volume between July 2020 and June 2022, according to its own needs, CATL said in a stock exchange filing, the agreement does not impose restrictions on Tesla’s purchase volume.

Tesla, which has a long-standing battery supply agreement with Japan’s Panasonic Corp <6752.T>, said during its earnings call last week that its pact with LG Chem <051910.KS> and CATL was at a scale.

Tesla is building Model 3 vehicles from its $2 billion Shanghai factory, which started delivering cars last year, and has said it would diversify battery supplies for the plant.

(Reporting by Yilei Sun and Brenda Goh; Editing by Kim Coghill and Uttaresh.V)