iPhone 5S Bad battery drain

I have a iPhone 5S that is just over 1 year so its slightly out of warranty.

Ever since my update to iOS 8.4 I have had very bad battery performance. I get 4 hours usage out of it.

I have tried all of the following:

• Turning off iCloud, Location Services, Find my iPhone ect.
• Reset and erased settings.
• DFU Mode and updated to latest iOS.

Weird thing is that it only lasts 6 hours in airplane mode, something is terribly wrong.