I replied in another thread about battery life:
There have always been a lot of battery problems posted about in these forums following each and every iOS update. Personally, I believe that the battery really isn't discharging any faster, it is just that the charging circuit is confused and needs to be reset. I always perform a setup as a new phone for major updates, for example iOS3 to iOS4, 4 to 5, 5 to 6, which should be a 'reset' for the charging system, but I do a simple update for point releases--6.0 to 6.0.1, etc. I have never had a problem with battery performance when performing the full update as new, only when I did a 'normal' update for a point release. If I perform an update with a restore from the old backup after a major update the battery problem did appear.
After every iOS point update I always do a full reset--home and on/off buttons held down until the Apple appears--three or four times over the course of a couple of days. I allow the phone to fully charge overnight every night.
This has always resulted in 'normal' battery life after one or a few reset cycles. By 'normal' I mean that a fully charged iPhone, with email and other notifications enabled and set to push, and no particular attention paid to battery conserving techniques, will discharge to about 89% over a 10 hour day. If I make a few phone calls and surf the web a bit then the level has fell to 70% or so, but unless I heavily use my iPhone 5 it doesn't drop below that point.
Prior to performing the resets the charge level would sometimes drop into the 50's or 60's or even lower in a few hours without using the iPhone. This problem 'scenario' has happened with every iPhone I have ever owned and I've owned all but the original iPhone.
As always, YMMV. I make no claims as to its usability for anyone else.
I have taken your advice and restored my iPhone as a new phone.
I have charged it to 100% and I'm going to leave if it for the remainder of the day and monitor the battery life.
I have not synced it with iTunes yet i.e. no apps, email accounts, photos, music… etc etc.
So far so good. It has been sat on my bedside table for almost an hour and is still on 100%. Had this been yesterday, It would already by down by 10 or 15%.
I'm going to check on it this evening and see where its at. If it is still on a high percentage, I shall sync it with my iMac and start loading all my junk back on.
Any other tips? Should I stick all my old apps back on in one go or just add them as I need them?
Thanks again for the help and advice. I suppose I have just been lazy when new software updates have been available and just backuped and updated. Maybe this has been a lesson that its worth taking an extra bit of time to upgrade more thorough i.e. upgrade from new and start afresh.
Ironically, my wife upgraded her iPhone 5 'over the air' to iOS 6.1 and has had no problems.
Hi RobboMagic, I had the same problem after updating my iphone 5 to the newest IOS and could not understand what was happening with the battery and power, so I used the monitor function on my battery doctor pro app and found out that mobilemail was always running in the back ground even though I have double tapped the home button and closed the mail app down correctly. I would open the mail app then close it then double click the home button and close correctly and it would stop. After a while I would check in battery doctor pro and it would be running again!!!! Then by accident I discovered that every time I open up my "the weather channel app" it would start again so I closed everything down made sure the mobilemail process was not running and started "the weather channel app" and sure enough once I closed the weather channel app it had started again!! So I found out that another app was causing the problem. I deleted the weather channel app and then reinstalled and all seems to be good now. Hope this helps.
Hi Dan, thanks for your advice
I restored the phone as new this morning. The phone is almost as if it was straight from the store - all I've done is connect it to my wifi. No third party apps installed or running.
7 hours of the phone sat there doing nothing on my bedside table - down to 50%
Taking it back to the store tomorrow. Something serious has gone wrong with my phone since upgrading to 6.1