What Is Tesla's 'Million Mile' Battery and When Will It Be Revealed?

Elon Musk has teased fresh news about Tesla's Battery Day event after suggesting it will be "one of the most exciting days" in the company's history.

On Twitter, the billionaire boss of the electric car company said the reveal—expected to include confirmation of a "million mile battery"—could take place in two parts, with an initial webcast next month followed by an in-person event later in the year.

Musk suggested that under current conditions the previously suggested timeframe of May would have to be pushed back or attendance would be low, but agreed with one commenter who complained that streamed webcasts are "lame."

"People have forgotten how much in-person events matter! Also, there's a lot to see. It's not just a presentation," Musk tweeted, fueling anticipation about the new battery that is poised to offer a million miles of total use (not range on a single charge).

For months, speculation has swirled about Tesla's next steps in terms of energy tech, which should not only boost battery lifespan but lower vehicle cost.

Last November, Musk confirmed the company's electric pickup, the Cybertruck, would be the last product revealed "for a while," noting that Tesla would be focusing on some "mostly unexpected" announcements in 2020. Last month, he said the next event could be solely based around batteries, noting there was a "lot to talk about."

Reuters revealed last week that Tesla is currently planning to introduce a low-cost, long-life battery in its Model 3 sedan in China later this year or early in 2021.

According to the newswire, the move will bring the cost of the electric vehicles closer to its gasoline rivals and the batteries will have "cobalt-free" chemistries.

Musk said in 2018 the next-gen batteries should use zero cobalt, which is expensive and often mined in conditions that violate human rights.

During a Tesla event last year that focused on the cars' self-driving capabilities, Musk referenced next-gen batteries, stating that new packs are "probably going to production next year" and will be "designed explicitly for one million miles of operation."

Reuters reported the battery tech was developed by China's Contemporary Amperex Technology Ltd., and a team of "academic experts" recruited by Musk.

They included Jeff Dahn of Dalhousie University, who previously led research indicating that a one-million mile battery was feasible, backing up Musk's claims.

The latest breakthrough, sources told Reuters, is due to "chemical additives, materials and coatings" that help batteries store more energy for longer periods of time. The exact specifications of the Tesla "million mile" battery remain unknown—for now.

Reuters reported it is expected versions of the battery will eventually be introduced into more markets, including North America, but timescales are also a mystery.

According to Tesla's website, the Model 3 offers a full-charge range of 348 miles, with battery modules Musk says can last between 300,000 to 500,000 miles.

When the CEO was asked about the Battery Day event during the Q1 2020 earnings call he decidedly kept his cards close to his chest—but promised big.

"We don't want to pre-empt Battery Day," Musk said on the call. "We want to leave the exciting news for that day, but there will be a lot of exciting news to tell."

"And I think it would be one of the most exciting days in Tesla's history and we're just trying to figure out the right timing for that," the CEO continued.

He added: "We think probably the right timing will be the—probably the third week of May. Not giving a firm date, but we think that probably that's the right timing. And depending upon what we're allowed to do, it will either be in California or Texas."

Tesla has been contacted for comment by Newsweek.

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Electric cars of U.S. automaker Tesla stand outside the Hangelsberg community center during a Tesla recruitment and employment information evening on February 5, 2020 in Grunheide, Germany. Sean Gallup/Getty