Tesla is planning to build a new battery manufacturing facility in California as part of the company’s efforts to make its own automotive batteries.

Tesla’s CEO Elon Musk has said earlier this week that they will give a tour of Tesla’s battery cell production on September 15, which the automaker calls “Battery Day”.

Previous reports suggest that the carmaker is going to announce a new low-cost, long-life battery pack that will have the ability to last for one million miles.

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Tesla Model Y

According to the EV maker, they already run a “small-scale” battery manufacturing operation in Fremont but documents seen by Reuters revealed that Tesla has applied for city government approval to build an expanded battery-building operation, with the project dubbed “Roadrunner”.

The facility will employ up to 470 workers, of which 400 “work in shifts, such that there are 100 employees working at manufacturing and production operations at any given time, all day, every day.”

Tesla is currently manufacturing batteries in collaboration with Japan’s Panasonic at their Gigafactory in Reno, Nevada, and has also contracts with South Korea’s LG Chem and China’s CATL. The company has recently signed a new three-year agreement with Panasonic over the production and supply of battery packs at the Gigafactory.

The company has also broke ground at its new Gigafactory in Berlin, Germany, which is expected to be ready next year, targeting a production launch as early as July 2021.