IOS 7 is draining my battery way too much?

Since I updated my phone battery has been draining so fast, I really do hate ios 7 I wish I could downgrade I would buy a brand new phone so I won't be stuck with this. But I don't know if it would already be updated. Anyways I've closed all my running apps except safari because I'm using it right now and when I charge my phone I close all my apps and my brightness is as dull as it can get. I let my phone die all the way then charge it to 100% but it still dies fast my phones on 17% right now and I unplugged it at 2 something and it's 5:42 at this moment so it's been about 4 hours if you round it. I've tried a app but it made no difference at all! If I buy a brand new one and give this one to somebody will it have iOS 6? If it does I'll probably get it off amazon this time, btw it's iphone 4:) also is iphone 4 or 4S better because I might get 4S if it does have ios 6

Added (1). OMG I'm sorry wrong category

I have an iPhone 4 and its battery life is terrible. You can't do anything about it. Just suck it up, bic boi.

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