iPhone 6 Usage times incorrect

Got an iPhone 6 two days ago and immediately found the battery life to be poor. I have just reloaded iOS 8.1.2 and set up as a new phone. I haven't installed any apps and have only activated my iCloud and Gmail account, both of which run on hourly fetch schedules. Background app refresh and location services off. I do have bluetooth on as I use handoff with my iPad and Mac. In the last 1.5 hours since installing the software, my phone has 37 minutes of usage, despite me only having ACTUALLY used the phone for about 10 minutes. Any idea why this might be the case?