If you have an iP5 running iOS6 and you have virtually every single background notification turned off, you can expect to lose about 10% an hour screen on time for regular use and web surfing (not including games which drain the battery much faster).
That's about 10 hours of battery life in optimal conditions. You can read that stat in several places (http://blog.gsmarena.com/apple-iphone-5-battery-test-is-done-proves-itself-as-a-thin-powerhouse/). It's fairly accurate compared to what I've had myself. Most people won't see this though because they run so much stuff in the background like e-mail, Facebook, weather, stocks, etc. I don't care for that. I just check those things manually when I feel like it.
Since going from iOS6 to iOS7 I've noticed a very small loss in that level of battery life. Thankfully I haven't come across the battery bug others have. I just turned off all background task tonight though so we'll see how it does tomorrow.
tl;dr:
On an iP5 with iOS7 you can expect some pretty damn good battery life... Assuming you don't come across any bugs and you don't have a lot of functions running in the background.
That's about 10 hours of battery life in optimal conditions. You can read that stat in several places (http://blog.gsmarena.com/apple-iphone-5-battery-test-is-done-proves-itself-as-a-thin-powerhouse/). It's fairly accurate compared to what I've had myself. Most people won't see this though because they run so much stuff in the background like e-mail, Facebook, weather, stocks, etc. I don't care for that. I just check those things manually when I feel like it.
Since going from iOS6 to iOS7 I've noticed a very small loss in that level of battery life. Thankfully I haven't come across the battery bug others have. I just turned off all background task tonight though so we'll see how it does tomorrow.
tl;dr:
On an iP5 with iOS7 you can expect some pretty damn good battery life... Assuming you don't come across any bugs and you don't have a lot of functions running in the background.