I used to rave about how great my iPhone 6 battery was. Suddenly after a year it's useless. Not on a gentle slope to useless, but it's gone from having 50% left at night to needing charging at lunchtime. Anyone else having this issue? If I were cynical I'd note how all my iPhones had done this around the time the 'S' version appears. But that must be coincidental. Must be... Cheers.