My iphone 5 battery is so poor?

I brought my iphone a week ago and the battery doesn't even last a full day! It lasts about 7 hours then dies! Why is this? I've turned everything off i could and restored it but still causing me problems? Could someone please help?

Oh it's normal because it's touch oh and if you're not using the wi-fi connection turn it off because it need a-lot of charge so that's all i can help you with oh and one last thing turn off the phone when it's charging so it'll charge faster
i can't give you any more advise because i'm not a mechanic or an engineer.
hope this helped you

Sounds to me like you've been using the iPhone up until its battery died. If so, that looks just about normal. If not, take it to an Apple store or Apple-authorized repair shop.

I'm having the same issue with my iPhone 5. I got it as a Christmas present but a month early and mine is shocking too. Though iOS 6.2 was released a few weeks ago and it's in the news that is effecting a lot of the iPhone 5 users.

But try some of these:
*Double tap the home button when unlocked, hold onto your apps until they jiggle and then tap the red circle to close them down properly (If you haven't already)
*Turn off LTE
*Turn off push notifications for apps there's no need for
*Turn off certain iCloud settings
*Run your battery down to 0% and then charge it up to 100% undisturbed
*Totally reset your device and start again
*Reset your network settings

For some people, they work, for others they don't. I always run down to 0% anyway, I only sorted out app notifications today so it might fix, but the rest of them I've tried and it has made no difference. If not, I would wait and see what updates Apple release within the next coming weeks/months and see if they fix battery issues, if not, then I might take a visit to an Apple store, even though my nearest ones are 39 miles away and the other is 43 miles away, so I really don't want to.
Also, I've asked these three questions below in three different categories just earlier, so if you want to keep watching those to check and see if I get different answers to you and I'll add this one to my watch list too for the same reason, let's hope we get the answers and help we need!