The discovery was made by a Reddit user named Tom, who decided to reduce Apple's smart battery pack for the iPhone 7 to fit the iPhone X. Not only did the case function but it also revealed the iPhone X-esque Smart Battery Case icon with slimmer design and vertical camera cutout.
Apple ended the iPhone X in September, so the icon probably applies to the iPhone XS, which has the same physical design.
The icon appears to be the same as was discovered in watchOS code by 9to5Mac s Guilherme Rambo , although this time in action on an iPhone. The new case seems to have a lightning contact, but no "hook" extends under the iPhone.
Rambo also revealed references to three model identifiers for the case in the iOS code, including the A2070, A2071 and A2171, suggesting that Apple could release the case in three different sizes for the iPhone XS, iPhone XS Max and iPhone XR. Another identifier allegedly indicated by a 2018 release that did not happen.
Images of possible iPhone XS and iPhone XS Max Smart battery cases were also revealed in a Fall 2018 merchandising guide for Apple retailers.
Apple has never released a smart battery pack for a large-sized iPhone, and the larger iPhone XR and iPhone XS Max already provide longer battery life, so the new case may be for iPhone XS only if released.
Apple's first Smart Battery Case was for the iPhone 6 and iPhone 6s, and was equipped with a 1.877 mAh battery that shook off the back of the case. Apple later released an iPhone 7 version with a similar design but larger 2,365 mAh battery. Both are still available for purchase for $ 99 in the United States.
Now there has been much evidence that Apple has at least considered releasing a smart battery kit for the iPhone XS. Whether the plan is going to work, there is still a release.