Battery problem after using iOS 4.2

[greygray]

Hey all, just need to ask for advice. My iPhone 4 has been experiencing rather bad battery life after downloading iOS 4.2. Here's the stats. My iPhone's brightness level is 1/7 of total brightness, 3G enabled, wifi and bluetooth off, no active apps. I fully charged my phone, left it in sleep mode for 8 hours without using it at all, then when I checked, battery life had already fallen to 85%.

Is there a problem with my battery life?

 

[blackberrypilot]

You need to setup as a new phone in iTunes. Its the only workaround this lame bug. I read its corrupt metadata from when you upgraded.

I would reformat, and setup as new phone.

 

[Bored Op]

I thought I hadn't plugged my charger in correctly

for us dopes, I understand how to backup my iPhone, but what do you mean by reformat?

 

[blackberrypilot]

Just plug in the iphone into iTunes and hit restore, then setup as new phone. Should be like turning the phone on for the first time out of the box.

 

[Bored Op]

restore

got it. Thanks.
will I lose anything, such as old txts?

 

[blackberrypilot]

You'll lose everything. It will be no different than turning your phone on for the first time. It sucks, but it seems to be the only work around for the 4.2.1 battery drain.

 

[greygray]

Hmm alright, thanks!

 

[benhollberg]

What if I restore my iPhone then when I plug it in again restore it from an older back up?

 

[greygray]

UPDATE: I restored iOS 4.2 and it's working fine now, after fully charging my iPhone, and 21 hours of standby with a little bit of usage, my battery now shows 96%, which is awesome! Guess it was a bug in my previously downloaded OS that screwed my iPhone's battery life for a while!