I have had my iphone for only 6 weeks and I have been loving it !! however, in the last 24 hours, it has begun to rapidly lose battery power all of a sudden, and it is getting worse - eg this evening i recharged it to 100%, and within 15 minutes it had already gone down to only 75% battery left!
Please help !! have i touched a setting I shouldn't have or should I take the phone back to the retailer to look at the battery?
Likely a hung or runaway process. Try a reset. To reset the iPhone, press and hold the home and sleep/wake buttons until you see the Apple logo (ignore the slide to power off prompt).
I am having the same problem, which just started in the last 4 days. I did a restore with no success. Prior to I was having no problems. This morning I went from 100% to 17% in about 3 hours with 1 hour of usage.
As Neuro said, you have a runaway process (or possibly corruption in the network settings). There are a few things to try, one at a time:
1. Reset Network Settings. This will require re-entry of any network passwords, but is otherwise harmless.
2. If you use Push email (Exchange, gmail, Yahoo or MobileMe) go into Settings/Mail, Contacts & Calendar, open the account and turn it off. Then reboot and turn it back on.
3. Turn off Notifications in Settings and reboot. If this fixes it turn it back on and turn off settings individually for the apps that use it until you find the offending app.