Poor battery life on new iPhone 4? Make sure you restore as a new phone...

[louis]

When I bought my iPhone 4 last week, I almost immediately realized how quickly the battery was draining. Not even my 2 year old iPhone 3G was losing its juice at such an accelerated pace.

To give you an idea, I was losing 1% every 3-4 minutes while surfing the web on Wifi. This was with push notifications, location services and 3G data turned off, all background apps killed and brightness set at 1/3. Apple's claim is roughly 10 hours of internet use on Wifi, so I knew my 5-6 hours was drastically off from the norm.

Several searches on Google later and it's become apparent that quite a few iPhone 4 owners are complaining of poor battery life. Now there are many variables for a quick drain, but after some research, I found that 3G owners upgrading from iOS 3.x.x to 4.0 could have issues with the backup data that's subsequently created (especially on iTunes 9.2). And if the iPhone 4 is setup from said backup, there's a good chance of poor battery performance. This is exactly what happened to me. Realizing my "mistake", I wiped my i4 and chose the "Setup as new iPhone" option when restoring.

Thankfully, my iPhone 4's battery is now performing up to expectations after the complete iOS reinstall. Rather than the 5-6 hours I was getting, it's back up to 9-10 hour mark on wifi.

So if you feel your battery is not up to snuff, I'd highly recommend that you restore the the i4 as a new phone (if you did indeed use backup file from 3G/3GS when first setting up). Also, some apps do run in the background and can cause the battery to drain, so kill all background apps first to see if it improves the battery life.

And if all else fails, set up an appointment with Apple and let the "geniuses" take a look. It's possible that you picked up a defective unit (aka lemon)

[ChiffaN]

As I always reccomended in my Upgrading your jailbroken phone without loosing savegame data article - always do the Set up as a new phone after an upgrade and use the various Jailbreak tools, described in the article to move the data - you're guaranteed a much cleaner running phone!

[NK@TelephoneTechnologies]

Is your IPhone 4 connected to an exchange account? If so, easy fix to rectify battery and get excellent performance.
1. Simply delete exchange account
2. Completely shut down IPhone and leave off for 10 seconds
3. Reboot IPhone
4. Re-enter exchange information
You will now have dramatic improvement on IPhone.
When Apple introduce a new OS upgrade, and you preform this upgrade on your handset, the bug will re-appear. Simply follow steps above and all will be fixed again.
Please let me know if you battery performance has been resolved after following these steps.