Chinese automaker Nio on Tuesday revealed that a 150-kilowatt-hour battery pack and a next-generation battery-swapping system will be rolled out with its upcoming flagship sedan.

Previewed with a shadowy teaser image, the sedan will debut as part of the Nio Day event January 9. Until then, the company is keeping most other details—like any hint about driving range—under wraps.

Announcement of the 150-kwh pack comes shortly after Nio launched a 100-kwh pack for its current electric cars in late 2020.

Originally known as NextEV, Nio generated buzz with the low-volume EP9 supercar and a Formula E race team, then went on to develop the ES8, ES6, and EC6 crossovers. It had big plans for the United States, going public on the New York Stock Exchange and discussing plans to sell cars here by 2020. Those plans were put on hold, however, after the Chinese government cut car subsidies.

Nio Power

Nio Power

Under a new twist to its business model, the company is offering the 100-kwh pack for lease, as a separate transaction on top of the sale of the car. Existing customers with 70-kwh Nio ES8, ES6, and EC6 electric cars can upgrade to the 100-kwh pack for a monthly fee (or buy the pack outright), while new customers get a discount on cars went they opt for the battery lease.

It's unclear if Nio will offer a lease option for the new 150-kwh battery, or if that battery will be offered on other models beyond the flagship sedan. But Nio did confirm that battery swapping will be available.

Nio has found success with battery swapping in a way no other automaker in the world has so far. It completed its 500,000th swap in May of last year. In China, Nio Power partnered with another Chinese EV maker, Xpeng toward the eventual merger of their charging networks in late 2019.

Is the combination of a huge battery AND battery swapping overkill? Or would you like this level of flexibility in a next EV?