iPhone 3g iOS4 Battery life

the fix I found for this is to reset your network settings. I've had this happen twice on upgrade and this has fixed it both times.

settings>>general>>reset>>reset network settings

My phone was running hot and battery was dying in a couple of hours. Now it's 100% back to normal.

hope that helps
Alan

tried this but doesn't look like it's made any difference. i literally watched the % drop by 2% while looking in the settings menu after.

Had the same situation when i upgraded my 3Gs. Noticable drop in battery life even while doing nothing. I have reset the settings as suggessted by another contributor to this thread and will monitor it. Also turned off Wi Fi etc but, if we turn off all these functions what's the point in having one?

This has definately put me off going for the latest iPhone as i had expected Apple to do significant work to resolve the battery issue and, to expand blue tooth so we could transfer files (not just via 3rd part apps which do iPhone to iPhone connection only).

I have been experiencing the same issue since upgrading to the new OS on Monday but I have tried to play with the notification, I turned them off for some apps which I may not need them but that did not help. I ended up turning off notifications from settings and it seems to help.

I would suggest turn of notifications and then reboot. Please post your results.

Thanks,

Hawk_Eye wrote:
I suggest if you have any app crash you should reboot the iPhone to force the connection and anything else that happens to be left over as a result to be cleared up.

LOL... Reminds me of Windows 3.11 😉 Congratulations, Apple.

Problem Solved!!!!

Double click the home button. Hold on one of the apps until the red minus circle shows then close them all by touching the red minus circle.

Every app that was open is running in the background..

The problem is usage of data in the background. I found out the apps that use your location continues to run in the background using up the battery life and also increases your data rate if you don’t have an unlimited data plan. For example, in 3.1.3, Trapster would run my battery down when I had it open, now I have to do an additional step to close Trapster in the Multitasking bar. To answer the million-dollar question, battery life loss has to do with multitasking. Under multitasking, many apps don't completely quit when you hit the home key. So if you find your battery draining a lot faster than usual, close all your apps in the multitask bar.

Your solution of closing apps doesn't sound like a very good solution. I thought this was supposed to be multitasking "the right way."

Having to do what you're suggesting means it's not implemented vey well.

Plus I disagree that all those apps listed when u double click home are running. Why then does it list apps in that tray right after I power the phone on?

Interested in comments on this n

Closing apps will fix the draining battery.

if you do not want to close apps.

then dont complain about battery life.

simple

If apps are showing in the multitasking tray when the phone is powered on--including apps I never use--how can I determine what apps are ion and need to be closed????

I don't think those apps are "running."

Only certain apps are allowed to keep going in the background. Is it possible to see which apps are truly running????

"Problem Solved!!!!

Double click the home button. Hold on one of the apps until the red minus circle shows then close them all by touching the red minus circle.

Every app that was open is running in the background..

The problem is usage of data in the background. I found out the apps that use your location continues to run in the background using up the battery life and also increases your data rate if you don’t have an unlimited data plan. For example, in 3.1.3, Trapster would run my battery down when I had it open, now I have to do an additional step to close Trapster in the Multitasking bar. To answer the million-dollar question, battery life loss has to do with multitasking. Under multitasking, many apps don't completely quit when you hit the home key. So if you find your battery draining a lot faster than usual, close all your apps in the multitask bar."

Everytime I click the homepage twice and hold an app down, I only get the "X" to delete.

Where am I supposed to see the red minus sign?

Duh. Nevermind. He's talking about multi-tasking in the wrong forum. 3G users don't get that function.

The iPhone 3G doesn't support multitasking under iOS4, so double-clicking on the Home button won't open the task manager. This solution would only apply to the 3GS.

At least you can get access to our phone. I upgraded to OS4 yesterday and charged my phone overnight and went out today. By 4 hours the phone was dead, not just flat. I have had it on charge for 2 hours and no signs of life yet. Could this be related to the upgrade or is it a co-incidence? Any ideas?

Exact same problem with a 3GS. Upgraded to iOS4 last night, put it next to my bed with the phone 100% charged, put phone to sleep. Wifi was off. The next morning, battery had completely drained. Plugging it into a computer got it to boot again, but I spend most of the day today attempting to restore it and fighting various reboot and recovery mode loops. Despite being connected to various computers via USB for 6 hours, charge never went above 3%. It eventually went down to 1% while still connected, and is now a brick. Won't respond to any computer or charging system at all, no recovery mode, no anything. Battery life and behavior was perfect right up until the moment I installed iOS4 last night.