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Tesla Battery Day set for September, Elon Musk says

Battery Day is rumored to bring news on Tesla's "million-mile" battery.

Big battery news could be just a few months away.

We'll likely hear some big news about electric car batteries at Tesla's upcoming Battery Day, which now has a tentative rescheduled date. Battery Day was originally supposed to happen in April or May, but Tesla and CEO Elon Musk didn't make mention of the event as the coronavirus pandemic set in.

Musk said on Twitter this Sunday that Sept. 15 will be the day we learn about whatever Tesla has in store for this event. The main rumor has it the event has something to do with a "million-mile" battery. China's CATL has supposedly worked with Tesla to create such a unit, and the company said earlier this month it's ready to build a battery with enough energy to go 1.24 million miles.

However, CATL didn't mention Tesla. But that could be because Tesla has its own version with help from CATL it wants to announce during its Battery Day. It's rumored that this cobalt-free battery will first show up in Chinese-built Model 3 vehicles, and then possibly head to cars sold in other countries.

Aside from a possible million-mile battery, we've also heard about Tesla batteries that won't use cobalt to reduce costs and some rumored charging technology to help cars give back to the grid when possible.

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