My battery life isn't good on 4S: anyone else?

Hello everyone. I have an iPhone 4S with iOS 8.1. Overall I'm happy with it, speed is still good and I find it to be nice and smooth still.
BUT...... I Have one issue: battery. I checked one day when I was at 30% or so, and I had around 3 hours of usage. Is this normal? It seems the battery is always dying! And also I have replaced the battery: just a few month ago so it Is nice and new. Another example, today I was fully charged, and by around 1:00 pm (I turned it one around 7am) I was at 57%. And I had around 1.5 hours of usage. Is this normal, maybe i'm over-exaggerating but it just doesn't feel normal to me.
Also how do I calibrate the battery? I've let it die and then charged it to 100%, but not sure if this is the correct way to calibrate.
Thanks

Applejuiced said:

How many years did you have it?
Maybe the battery has degraded and does not hold charge the way it used to.

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It was originally bought in 2012 ; but like I said the battery was replaced a few months ago.

Tyler23 said:

Replaced where?

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Repair shop in TN; I was on vacation and had to have it done cause the battery was really bad.

Tyler23 said:

Sad to say but often times these repair shops will use lower quality batteries, or sometimes even used batteries for replacements. I'd likely get in touch with the shop as clearly it's an issue with the battery they gave you.

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Hmmm, well I guess I could try to contact them but it might be tricky considering I'm in FL. Worth a shot though.

ifanme said:

The device battery isn't that bad as you've mentioned. My dad has a same device but the battery duration is almost a day with normal usage.

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So what should I do: take it to the Store and have the battery looked at?

Applejuiced said:

I dont know if that's a good idea.
They will see that it has an aftermarket battery and has had unauthorised service done to it and will just turn you away.

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Apple authorized service provider?

Applejuiced said:

The only one authorized to make repairs is Apple themselves.
You said you used a 3rd party repair shop in TN right?

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Yep. But aren't there officially authorized service providers? When I talked to AppleCare they said that there were some repair shops officially authorized by Apple