I’m hearing a lot of moaning and teeth-gnashing about how the new iPhones can’t hold a charge any longer than a two-year-old with a weak bladder (e.g., this report). After the first day or so I was a bit worried: I charged my iPhone 6 Plus completely before going to bed on the first day and the next morning it was down to 78% charge after sitting completely unused all night.
The next day charge seemed to go down somewhat faster than it did on my iPhone 5, too. But then things began to change, and last night I completely charged the iPhone 6 Plus again before going to bed. This morning, the reported charge was 100% — it barely dropped at all. Right now, in fact, it is still indicating 100% charge after 43 minutes of usage and 10 hours and 48 minutes of standby.
Seems to me that it takes a while for iOS 8 and the iPhone to settle down. It also seems to me that as the onslaught of background app updates slows down (only a couple apps updated last night), battery life gets better (I didn’t take Adam Engst’s advice to turn off automatic updates for iOS 8 because I wanted to see what the result of leaving them on would be).
All this to say that over the next few days I’m sure we’ll be seeing all sorts of scare stories about bad iPhone 6/iOS 8 battery life problems, but take them all with a grain of salt: it’ll take a week or so of use before you can have a reliable baseline of battery life information.