I have an iPhone 4S. Previously when running on ios 5.1.1, my battery would drop at most 1-3% after a full cycle charged. i even set everything off or limit the iphone background usage. For exp: Only default notification is ON. Installed apps req notification is off, diagnostics & usage turn off, reduce the brightness & ON auto-bright, Location service is off, wifi off normally but ON only to surf, change to default wallpapers, force close all background running apps, clear or reset statistics every night, clear all recent call list, clear all messages. copy messages that are important to notes.
By doing this as from my experiences, my battery life drops 3%. unlock the lockscreen is faster, launching apps is faster. multitasking or surfing is also faster depending on our local 3G speed. i also clear safari cookies & data & also history to make surfing faster.
Everything i do is faster. i maintain my free space to 11GB. My usage is only 2GB++. When i feels like my photos are many or my video is taking up my space, i transfer all to itunes & i create another copy of my photos & videos just in case of accidents happens. So.. my 4S runs fast again.
Now.. as i upgrade to ios 6, my battery life drops to 2% & by doing the things above, it feels abit faster then before.
I have noticed the same issues: since iOS6 a huge battery problem. Only able to use my phone for 4 hrs (standby!). Switching off location services doesn't help. Als disabling WiFi and Bluetooth has no effect.
But: Flight mode does help! No battery drainage when I have flight mode switched on...
I also noticed that my phone is warm, just like when I'm charching it. I have never had this, until iOS6.
I also tried to reset all settings, but without success. Now I've decided to completely erase my phone, without restoring a backup from iTunes. But then all my app data (like my Nike+ runs) will be gone...
Too bad Apple for not providing a solution for all the people in this discussion.
Ok guys, I think I have found the solution.
It might be mentioned earlier in this thread, but I can't find it. Just do as descibed in this post: http://tidbits.com/article/13303
What I have done: put my iPhone in DFU mode (see Post). Set it up as a new phone ans then restore my most recent backup. Guess what: Now in 5 hours only 15% battery usage! Before the 15% went gone within one hour! So for now I'm happy, also because of my backup restore I have all text and whatsapp messages restored.
Just erasing all data from your phone doesn't help (tried it!).
I have the same problem. I am so upset. My phone usually stays fully charged by the end of the night and after not even using my phone, by 3pm its completely drained. I wish I can undo the upgrade. If anyone knows how pleaseeeeeeeee tell me!! I wish I can just erase ios6. We should've been warned. Shame on you apple for not fixing this bug by now!