Has anyone else noticed more severe battery drain on iOS 8.0.2 on the iPhone 5S? Within 10 minutes or so of using Safari I'm down from 100% to 92% (this is an estimation - I haven't made a note of how long it takes to drain using specific apps yet). This phone was new when I bought it, but the warranty has run out recently (it was bought off eBay). It's a shame iOS doesn't have the power of OS X where you can see exactly what is causing this.