I got the iPhone 5 one week after launch, battery life was great for 2-3 weeks, I didn't install any iOS updates, no new apps that I hadn't used before, but out of the blue the battery started acting up and my phone would heat up. A full charge at 9 AM in the morning would be drained out by 3 PM. I turned off Bluetooth, location services etc, restarted phone, nothing helped.
Took it to the apple store, they asked me to restore as a New iPhone. Did that, Battery worked fine for a couple of days, but the issue re-occured soon after. I took it back to Apple got a replacement phone. The Genius Bar folks have no clue how to solve this btw, they told me it is a huge problem and is being caused by corrupted software (app or iOS not sure). So after I got the replacement phone, set it up as new phone, added my apps and **** no, same freaking issue. So I restored it once again and decided to troubleshoot it myself.
Here's what I knew about the issue -
- Battery Drains, phone heats up. (Phone Heating Up is the cue here folks, so if it feels hot, you have a problem)
-Internet Based, coz when I go into Airplane Mode, the Battery Life improved substantially, phone didn't heat up.
- I have on multiple occassions, turned off all apps, Bluetooth, restarted and yet the phone would continue to heat up and drain, so I doubt its an app, rather some settings in the iOS which use the Internet.
Here's what I did -
Connected my phone to Itunes, set it up as a factory restore and set it up as a new phone. iCloud restored all my contacts etc., added the apps I normally use (Maybe 3 pages of apps).
Then I went into settings for iOS and changed some settings, here are my current settings -
Airplane - OFF
Wifi - Connected (Though it doesn't matter much if you're on LTE/3G/Wifi
Bluetooth - Off (I only turn it on when I'm driving)
Notifications - I turned off notifications for all apps I didn't need 'em from
General - iOS 6.0.2
Limit Ad Tracking - Off
Diagnostics and Usage - Don't Send (This might be the key)
Siri - ON, Raise to Speak - Off
Cellular - ON, Enable LTE - On
Brightness - Auto
Privacy - Location Services - ON
I have it turned OFF for all Apps except -
Facebook, Maps, Shazam, Waze, Siri, Weather, Yelp, Find my iPhone
iCloud
Mail - ON
Contacts - ON
Calenders/Reminders - ON
Safari - OFF
Notes - ON
Passbook - OFF
Photostream - ON
Documents and Data - OFF
Find my iPhone - ON
MAIL, CONTACTS, CALENDER - (4 email accounts)
Push - OFF
Fetch New Data - 30 Mint
Facetime - ON
Comparison of Battery Life - (with same amount of Usage) on the SAME PHONE.
BEFORE - Full Charge overnight, 100% at 9AM, 60% at 12AM, 20% at 3PM, Fully Discharged by 5PM
NOW- Full Charge Overnight, 100% at 9AM, 60% at 6PM, 40% at 11PM, still 25% at 9AM the next day.
This is a really frustrating issue and I was literally pulling my hair out when this started happening, I had to carry my charging cable, everywhere I went. I've owned an iPhone 2G, 3GS, 4 and now 5 and this was the 1st time ever I had this issue or even had to go to the Genius Bar. I can tell you that this is definately a Software Issue and the Apple folks dont know the answer yet.
Try out these settings, make sure you set up the phone as a new phone before you do these settings and report back on the Usage.
Good Luck..!