As customers around the world begin receiving Apple's
iPhone 7 Smart Battery Case, it has now been confirmed that the charging case is rated for 2,365 mAh, ...
Chinese technical certifications revealed that the iPhone 7 likely has a
larger 1,960 mAh battery, as
previously rumored, meaning Apple's Smart Battery Case can charge the smartphone fully with roughly 17% capacity remaining.
If MacRumors is figuring the 17% as (2,365 - 1,960) / 2,365, that's not taking conversion losses into account. The circuitry is never 100% efficient, there will be some loss from components in the battery pack converting the energy stored in its battery back out to 5V to feed into the phone, and some additional loss in the phone from the phone's charging circuitry converting it back into energy stored in the phone's battery. Even if both ends of the chain together worked out to be 90% efficient, you're closer to 7% extra capacity remaining rather than 17%.
Still, if this case fit my use cases, I'd totally get one. I don't think it's ugly, but then I tend to see beauty in well-engineered things, irrespective of whether their surfaces are sleek. The case slims down at the ends, making it slide into the pocket easier and fit nicer when the bottom end is cradled in the hand while talking on the phone. If it were full thickness along the entire length, it would be less comfortable to hold and harder to carry. So the shape chosen maximizes storage while minimizing impact on use (and if you really hate the way it looks, no one is forcing you to buy it - we don't actually need 37 different comments saying it's ugly, you can just "like" one of the existing comments).
Compared to other battery cases, the integration into the system (charge with existing Lightning cable, battery and phone charge simultaneously and the phone uses the battery pack first, plus the phone can display the pack's remaining charge) is a big win, as is the ability to easily extract the phone from the case to switch to a lighter/slimmer case when the battery isn't needed (I know folks with non-battery Otterbox cases - because their kids drop their phones a bunch - and taking one of those off is an ordeal; my understanding is that some of the battery cases are similarly difficult).
*: (my use case being, my iPhone 6's battery does fine on its own throughout the day, but I often go out walking at night, frequently playing Ingress - which eats battery - and so
sometimes need a
lot of extra power; in this case, since I'm holding the phone out in front of me for long periods of time, having a large battery in a pouch on my belt with only the cable going to the phone, is lighter and more convenient to hold. If my battery was frequently running somewhat low during the day, when my phone was frequently in my pocket, Apple's battery case would be perfect.)