Just last week I got myself a new iPhone 5s (upgrading from an iPhone 4s) and everything's been great except that I have noticed that my battery drains extremely quickly during standby. I basically leave my phone above 90% and just over six hours later (enough to catch my sleep ) I am already down to 70%. A heck of a lot faster than I manage to drain by using the device. And this is having restored my 5s using iTunes from the first day and with all my settings the same as under my old 4s. Is this normal ?