iPhone 3g iOS4 Battery life

I agree, standby seems to not preserve battery life.

There should be an option to turn WiFi off on standby if that is the case, but I don't think that is the issue.

I'm also feeling the phone become warm while in pocket. I've "rebooted" twice by virtue of my phone running to -0- battery, and once from a manual shutdown.

I had similar problems so I "downgraded" back to OS3.

You can too!

Read about it on this thread: http://discussions.apple.com/thread.jspa?threadID=2473976&tstart=0

iPhone 3GS - iOS 4 - authorized carrier, Vodafone Italy.

Battery life is less than half than when I was using 3.1.3.

Help!

Same problem on my 3GS. Losing about 1% per minute with light use.

Everyone should tell apple, using their feedback form, http://www.apple.com/feedback/

More testing information:

With WiFi disabled, I still noticed that my "Usage" time increased while in standby, and still had a warm iPhone with rapid battery drain.

However, if I disabled cellular data, (not airplane mode), I had no usage increase while in standby and my battery didn't drain at all.

This seems to be a data transfer issue, something is causing the Internet connection to stay very active while in standby.

I Just notice this. I reset the usage data was 0 just 5 second I went back without opening any app and the data was 5KB then 30KB received and 15KB sent just like 10 second later and on.

What app would be causing this. I removed the "iBooks" app because of the "Sync" feature.

I notice one app is Crashing on iOS4 is the TextFree app.
Maybe could be the mail app on iOS4. I will try removing my email from the mobile and let you know

Interesting idea, Hawk_Eye. However, when I did my test and shut off all connectivity, I did not run any apps when I re-enabled connectivity and the battery drain & heat resumed. If it is a case where it was a stuck connection, it should have canceled when the data connection was dropped.

Let us know how your test works out!

It could be an application with the connection attempt "pending" when data comes back the app or whatever is just resume the activity so still could be.

Add one more name to the list: I just upgraded my 3G to IOS4, and my battery now goes from 100% to somewhere near 0%... in about 3 hours of little-to-no use. This is a big step-change from iPhoneOS 3.x behavior.

I'll be reverting to ios3 tonight... this is too far out-of-bounds.

And another...turned my 3GS off and left it on charge for 3-4 hours. Turned back on to find the battery meter showing 32%. Have tried the reboot idea previously suggested but to no avail. Leaving it charging on standby does seem to send the %age higher but it can then fluctuate with use. Come on Apple, you have GOT to sort this one out and quickly! I like folders on my iPhone but not that much...come back v3, all is forgiven!

i'm in the same boat. terrible battery life after ios4 udpate. there's gotta be a bug somewhere causing this. apparently the "limited" multitasking is not limited enough or not well implemented enough.

I thought this was only me!! OMG Apple has become so crap!!!It took them so long to release it, they had Betas and still its so ****... 😐

I had my itouch charged in my pc, it was full bar, once i went to bed and played around with facebook and emails it went half way, i went to sleep at 11pm and once i woke up the battery was on the low red bar.... that is shocking!!! i use to have my MSN+ running in the background on itouch have it running all night on standby and id still have green bars....... its not just the battery iv noticed but its when your typing something it laggs and sometimes freezes up... sometimes id press back space and it wont even work i have to press it 20 times then it works its so odd!!

I never had a problem till now.... All the apps arent updated so they all crash... why didnt they all get givin the correct codes so when OS4 came out, all the apps will be ready for an update....
I wont even bother thinking about iphone 4 if its going to be like this....
The folders are good though i must say that... but everything else... forget it.

For me it seems to be a 3G issue. I toggled it off and the battery drops less quickly. Then again it may be because the data rate is slower. Wi-Fi seemed to have nothing to do with it for me at least.

I noticed something similar on my April 2010 3GS. I rebooted the device, charged it to 100% and now I'm at 54% with 19h 44min standby and 1h 14min usage. This seems a bit less than with 3.1.3, but still okay...