I don't think the batteries are to blame here. The issue is that for every new recent iOS major release, they add additional (unncessary?) features. For example upgrading to iOS11 introduce a slew of extra animations. On my 6S, those animations (e.g. when you swipe left to delete a recent call) were noticeably choppy compared to my X.
I'm rationalizing that part of the REAL reason that Apple slows down your battery is to preserve the battery for support of some of these useless features. We should all know that the more animations something has, the more battery juice it will consume. I suspect they optimized the best experience for the newer phones, and maybe provide an adequate experience for earlier phones.
I'm rationalizing that part of the REAL reason that Apple slows down your battery is to preserve the battery for support of some of these useless features. We should all know that the more animations something has, the more battery juice it will consume. I suspect they optimized the best experience for the newer phones, and maybe provide an adequate experience for earlier phones.