My battery life has now drastically improved on the 4S!I have 26% life left after a full charge 24 hours ago (includes leaving on all night). This is about what I used to have with the iPhone 4. I have had moderate usage during this time, used Siri, check mail, browsed web, texted, and used multiple apps. After updating the software to the new iOS 5.0.1 my battery actually drained faster, like most reporting here. Upon my first full charge after the update I had a 12% decline in battery in one hour not even touching the phone for one thing. The first thing I noticed is I don't think the battery meter is very accurate. The meter drops faster in the beginning and slows down as you approach low battery. Then it hangs on 1% for a long time, almost like a reserve gas tank. Once I updated the new software I turned back on all my location settings to on. My screen is at full brightness, iCloud is on, Bluetooth off, 11 notifications (weather, messages, phone, ap mobile, facebook, cnbc, espn, reminders, calendar, mail, words free) on, location services on, with Facebook, gas buddy, maps, Siri, and weather on. All system services on, and find my iPhone on. I have not restored my phone once.
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My opinion is that the battery life has improved after a hand full of complete charges, and full drains of the battery. I believe this battery is getting better by running the full cycle, and because the battery meter isn't accurate it gives the illusion you have less battery life than you really do. Unless you have to have your phone plugged in and on, I had the best charge and life by plugging in phone to charge and then turning off the power for the night. This could be part of Apples glitch. That the phone appears to be fully charged by the meter, but maybe the phone isn't getting a full charge while left on? I also, double click the home button and kill all running apps, prior to shutting down and fully charging while off.