Sometimes the cause of rapid battery drain as you're experiencing can be caused by a stuck mail app or Safari. So, do this: First, open Safari & make sure there are no open pages. Leave nothing but a blank page. Then go to Settings>Safari>Clear History>Clear Cookies>Clear Cache. Next, Settings>Mail, Contacts, Calendars>Select your Mail Account/Accounts>Mail>Off. Next, double tap the home button to bring up the multitasking bar. Close/remove any and all apps listed. Tap the home button when finished. Last, reset your phone: Press the sleep/wake button and home button at the same time, keep pressing until you see the Apple logo, then release(ignore the slide to power off). This will kill anything that might be running in the background. Now, go back and turn your mail account back on. See if doing this improves things.
I had exactly the same problem last week in Germany and Austria. The battery died in 7h without any app visibly running, 3G, WiFi, data, push notifications, iPod EQ all off... It was very annoying since I really counted on the phone be able to alert friends on a skiing trip. The phone got also very warm. I rebooted it 3 times, did 5 full recharge cycles, nothing helped. It was very annoying...
I will try this tactic out when I am in Berlin next week for a business trip...
Thanks for the feedback.
I had the same problem last week in Swiss on a skiing trip.
All possible apps off. After 5-7 hours battery empty.
Several recharges, same problem over and over again.
All the time the phone feels hot.
Now I am back home, all normal apps on.
Phone tempurature feels good, only have to recharge after days.
Does anyone knows an App that can show which app or activity is to blame?
Device: iPhone 4 32GB, OS 4.3.1, never jailbreaked, data roaming always off
Same to me - at home in Austria no problems, standard battery runtimes.
During a one week trip to Dubai beginning with second day of stay my iPhone 4 battery lasted only for 6-7 hours without being used, I also observed hot temperature of the device and slow (sometimes hanging for seconds) operation.
As it was obvious to me that some app (from apple or third party) was running "hot" in the background, I tried to kill every running application by doing the following:
Safari clearing, deleting of local travel guide apps, killing all running apps in background via multitasking, shut-off of localization function, wifi, 3g, data connection, activation of flight mode, restart and reset of iPhone - without success.
Back to Vienna everything was fine again.
This was repeated during a trip to Jordan 3 months later. But I noticed that when the iPhone was connected to the hotel´s wireless lan the battery drain was interrupted, after leaving the hotel, it started again, not immediately but for sure after various periods (1 hour, 3 hours).
In both cases I did not switch off the the email app (connected with two exchange accounts including email, calendar, contacts) - although I meanwhile suspect it beeing the guilty one. Next time I will try the email account switch off method (including calendar and contact account sync).
Interestingly during the first trip two colleagues (1x iPhone 3GS, 1x iPhone 4, both with switched-on exchange accounts in email app) did not whitness battery drain on their iPhones (but I think they did have data roaming activated).
Anyway, very annoying / unacceptable to run out of battery during a private or business trip.
If this was caused by the build-in email app Apple should really have a look on this.