iOS 4 - battery drains much quicker after update

That's not my case. I even experience slightly higher battery life after the upgrade. That's strange, for you.

I have noticed my battery draining a lot faster. I have the standard 3G though without multitasking as an option. It appears there is something else causing it. I used to be able to make it through the work day, but am down to less than 20% by 1pm today with less use than normal. I am not very pleased with it so far. I am regretting the update because with the 3G I don't even get the better features. I should have just left it alone and waited for the 4 to come in the mail...

i have the same situation. although i added a second exchange email account so i dont know if that has anything to do with it. but if you type ios4 battery drain in twitter, you can find thousands of results.

Hello. Same problem to me. I have 3GS and I'm already at 30% today.

Yes, draining much quicker. Under 20% by 3 p.m. Seldom get to that point generally

I am experiencing this too! 100% to 22% in 4 and a half hours...

After having same battery issue I reset the phone ( sleep and home key ) and now it seems a little better ?
At least in sleep mode it only uses like 1% / hr .

Oops just used 4% in like 5 mins typing this, checking another thread and editing this !!!!! 

Omg no &%~>&@()** Way I need a days worth of juice !!!!!!

Message was edited by: myech

First try rebooting the phone (power off and then back on) and if that doesn't help, try resetting it by holding the sleep and home key until the phone turns off and the Apple Logo shows on the screen and let it reboot.

That *****. Hope you can find a solution soon!!!

same here. I was down to 30% after listening to pandora for a few hours today with the screen off.

Same case with me, with in a span of 3 hours it has taken by 70% of battery. I regret now to upgrade to OS4.

Same for me, 10% in half hour, very strange and not using that much. Before the update my battery lasts for 2 days with normal use.

just out of curiosity did anyone have battery issues before? When I first got my iPhone I had a series of problems I hadto exchange the phone and then again the second phone had issues later this year. I discovered Weather Channel Max and Pandora drained it rapidly. it was resolved by using straight up weather channel and no Pandora after a clean install. the Apps that use location services seem to have some strain on my battery. in the new iOS4 you can now choose what gets shut off in the settings under location services. I also did a reset and full charge last night to see what happens today But as of last night I am back to square one with this update. dropped from 100% to 45% in 50 minutes, then to 23% in an additional 30. It was in use setting up the new stuff. But this is worse than any battery issue to date.

Mine too, I was only able to watch 15 minutes of a Girls Gone Wild video before the battery was almost drained.

not happening to me but I did notice that several settings are different now on my phone than before 4. I would check all settings and make sure it isn't pushing or other things that you don't need it to do.
Hope that helps.