In recent years, a battery case was almost a necessity if you had an iPhone. However, this year, Apple has gone to great lengths to thicken the iPhone 11 range of products so they can each be equipped with higher capacity batteries. In fact, the battery life on the new iPhones is so good that you may not need or buy a battery box.
9to5 could not figure out how much battery life the cases will provide for each iPhone and when Apple will release them. However, the website speculates that Apple may announce the new case later this year along with the long-tracked tracking tags. The company did similar things last March when it launched the AirPods of the second generation, the 10.5-inch iPad Air and the 2019 iPad mini in the same week.