Tesla's Optimus Robot Everything From Tesla AI Day Bella Hadid's Spray-on Dress Hasbro's Indiana Jones Toy 'Hocus Pocus 2' Review AirPods Pro 2 Discount Meal Delivery Services Vitamins for Flu Season
Want CNET to notify you of price drops and the latest stories?
No, thank you

Tesla just built the world's largest battery, thanks to a bet

The lithium-ion battery in South Australia will be energised within days, all thanks to a Twitter bet between two billionaires.

Tesla Launches Powerpack Project In South Australia
Elon Musk at the Tesla Powerpack unveiling in South Australia in September.
Mark Brake/Getty Images

In July, Elon Musk bet the people of Australia he could build a 100MW battery in 100 days or it would be free.

Turns out the man who proposed using rockets to fly us around the world in 30 minutes is nothing if not ambitious. Tesla just did it -- with about 40 days to spare.

On Friday, the South Australian government announced the completion of the world's largest lithium-ion battery just outside the South Australian city of Jamestown. In a statement, the office of state premier Jay Weatherill confirmed the battery would be energised within days.

The battery was the result of a bet between Tesla CEO Elon Musk and fellow billionaire (and founder of Australian tech company Atlassian), Mike Cannon-Brookes. After a series of major power outages across South Australia, including a state-wide blackout that affected an area the size of France in September 2016, Cannon-Brookes challenged Musk to find a solution.

The deal to build the battery was struck over Twitter in March, Musk flew to Australia to announce the build in July and contracts were signed on Sept. 29, kicking off the official 100-day countdown. But by that time, Musk was hosting a party in a marquee in South Australia overlooking an already half-completed battery array.

The 100MW battery array, made up of Tesla Powerpacks, is connected to the nearby Hornsdale wind farm, operated by Neoen. Set to be launched by Tesla officially, Neoen and the SA government next week, it will then go through a testing phase to ensure it meets regulations.

Rebooting the Reef: CNET dives deep into how tech can help save Australia's Great Barrier Reef.

The Smartest StuffInnovators are thinking up new ways to make you, and the things around you, smarter.