iPhone 4S battery replacement without losing iOS 7.1.1

[iMacBooked]

My iPhone 4S is getting old now, and so is the battery: Almost 1.000 charge cycles done (986) and the max capacity is only 1197 mAh now, instead of the original 1430 mAh..
Is it worth buying a new battery in this case? Because I hear a lot of people claiming that it would be more like a placebo, and that since iOS 7+ you would never get the same battery power out of it as it used to be on iOS 5-6.
Is there any way to get a better view/calculation on what the improvement actually would be?
I mean yes the max capacity would go up from 1197 mAh to 1430 mAh then, but I suppose that doesn't actually mean I would get 16% more battery life out of it then, or is that really true?

Oh and about the replacement itself: I was thinking of sending it to Apple for a new battery (price doesn't matter), but I'm worried that this would mean getting iOS 8.1.2 on it.. right? I really like 7.1.1 jailbroken and don't want to upgrade at all, so does really everything you send to apple (even if it's just for a battery replacement) means you'll be getting the new OS on it?
Because if that's the case, the only solution is taking it to a third party repair shop who'll do it quickly and for a few bucks. But then again I don't know where the battery would come from, probably somewhere cheap on let's say eBay or something... The idea of getting a replica/non-apple battery scares me: I suppose cheap batteries aren't the same in quality and have increased risk on overheating?

Any help would be very much appreciated, thanks!!

 

[Max(IT)]

1197 mAh is a little bit low, but not so much.
I'd wait a little more before changing the battery.

 

[iMacBooked]

1197 mAh is a little bit low, but not so much.
I'd wait a little more before changing the battery.

Hmm I see, well it drains pretty quick though..
Also, the 1197 mAh is just information I got from a battery jailbreak tweak, so idk how trustworthy that would be, it's not like I tested it at the genius bar or something

 

[Max(IT)]

Hmm I see, well it drains pretty quick though..
Also, the 1197 mAh is just information I got from a battery jailbreak tweak, so idk how trustworthy that would be, it's not like I tested it at the genius bar or something

I use ibackupbot for that. Surely it has the same reliability of your jb tweak.

 

[BreeeZe]

It should be possible to backup your shsh blobs so you can reinstall ios7 yourself : http://www.ijailbreak.com/how-to-save-shsh-blobs/

 

[iMacBooked]

It should be possible to backup your shsh blobs so you can reinstall ios7 yourself : http://www.ijailbreak.com/how-to-save-shsh-blobs/

Lol, that's impossible. Without an iPhone 4 and since iOS6 that's not an option anymore.

 

[BrettApple]

I'd just replace it yourself or take it in to a third party. I replace batteries in iPhones (4,4s,5) fairly frequently. I used to get them from iPhone4Parts and they've been fine. My last one was a Stalion battery from Amazon. It also seems to work just fine.

If you do it yourself, you need a pentalobe screwdriver and a 00 driver. Easy to come by on the web and lots of kits are out there. A pry tool helps to get the battery free from the adhesive.

If you do send it to Apple, it will ship back with 8.1.2 most likely. I sent my 4s in back in November 2013 or so and they updated it to 7.0.X from 6.1.2. Data was kept intact, but if you're jailbroken I wouldn't be surprised if it gets restored and wiped.

Also Apple charges $80 plus shipping. That one on Amazon was $20, and I usually get the iPhone4Parts ones for $8-10, but they've gone up a bit.

Or they will just give you a replacement iPhone. Not sure how they go about it now. They could do either.

https://www.apple.com/support/iphone/repair/battery-power/