OK, wondering if anyone has any ideas. We went to LA a few days ago, and mom's iPhone has been draining REALLY fast as of late. Seems worse when we're away from home, even though cell service was perfectly strong (and no one else had an issue). We're talking an AT&T MVNO in a major metro area, after all. Go throughout the day, oops, it's almost out. Leave it unplugged overnight (when it was full before), oops, it's dead. Etc. Seems to have a fair bit of "usage" as well (keep in mind that Android only counts screen on, but iOS is different and counts more; I could be misinterpreting it).
But I plugged it into a Mac with CoconutBattery, and it has 92% of design capacity. She keeps things simple, doesn't have many apps installed, mostly uses it for texting, taking pictures, and looking a few things up (uses her iPad or laptop for more than that, doesn't play Pokemon Go, etc), and has been keeping Battery Saver on as of late. Still drains like mad, the rest of our phones are working just fine (i.e. I ran Google Maps/nav on my SE for a few hours, played with it a few hours, etc, and it still has a good bit of charge left).
Is it worth factory resetting the phone? Could it be a hardware defect?