IOS 4.2.1 battery drain

Today the usage time so far is about 3 hours and the battery is still on 70%, which is fantastic. It's much better then it was before. I will monitor the phone behavior for the next days and see what will happen. Do you think if I turn on gmail and hotmail accounts on again it will affect the battery life. I intend to keep the mail app closed (from the tack bar - double click).

Today the usage time so far is about 3 hours and the battery is still on 70%, which is fantastic. It's much better then it was before. I will monitor the phone behavior for the next days and see what will happen. Do you think if I turn on gmail and hotmail accounts on again it will affect the battery life. I intend to keep the mail app closed (from the tack bar - double click).

Just upgraded a couple days ago and noticed the battery drain is significant now. In a normal work day usage I would still have half my battery left when I got home, now I'm having to charge the phone right when I get in my car at the end of the work day!

I tried restoring the phone, but that didn't help the issue.

You should be able to turn the accounts back on after rebooting. The reason to turn them off was to kill stale connections that the mail app was trying (in vain) to retrieve mail on.

You must restore as new; if you restore and reload your backup you are just putting the problem back on the phone.

Here's a graduated set of steps to resolve high battery drain. Only go as far as necessary; it is rarely necessary to do all of the steps. After each step reboot the phone (hold HOME and SLEEP until an Apple logo appears, ignoring "Slide to power off"):

1. Settings/General/Reset - Reset network settings (you will lose WiFi passwords, but nothing else)

2. Settings/General/Reset - Reset all settings (you will need to reset some additional settings, but will not lose data)

3. If you have Push email accounts: Settings/Mail,Contacts,Calendar - tap on the account name and switch it off (the account, not Push). Open the email app; verify the account is gone (and let the mail app know it is). After rebooting, go back to Settings and turn the account back on. Wait an hour before testing to give it time to sync back to the server.

4. Turn off Notifications in Settings. Test for a day. If the problem has gone away you have an app that is using data when it shouldn't be.

5. If you have EVER launched Game Center go to Settings/General/Restrictions and disable Multiplayer games. You will have to set a passcode to do this; DO NOT FORGET IT.

6. Look at the apps currently in the quick launch bar. When on the Home screen double-press HOME. tap and hold any app so "-" signs appear. Kill any apps that might use background such as Facebook, Skype, Yahoo, music streaming apps, etc.

7. If you have gotten this far and not fixed it you probably need to restore as New.

Hey Lawrence, you mentioned that the possible culprit for this issue is a bad meta data. I'm wondering, did the bad meta data happen during the update, or was it already there? Thanks.

I'm not sure where corrupted metadata comes from. I suspect the update uses memory that was not used previously and had random data in it prior to the upgrade. After the upgrade unless that memory is reinitialized it can cause problems. But it could also be in the backup, which would explain why restoring as a new phone usually fixes the problem.

I have done a non scientific test and turned all push off for a day and didn't notice any significant difference in battery life than with push notifications on. I get about 7-8 hours of usage on the phone consistently. I will leave push on now because I use a lot of apps that use push and it seems to work as advertised and doesn't use much battery. BTW I am using 4.2.1

I ended up rolling back to 4.1.. Pain in the a** b/c I lost all my app data, but it seems to have returned my battery drain back to normal.

Thats the last time i'll jump on a new firmware upgrade for iPhone right away...

That's interesting. In my previous 3 3GS iPhones, I've restored in each one as new but it didn't fix the issues with 4.0 - 4.1 (fast battery drain, reboots, wifi and 3G issues). When I got upgraded to the iP4, I restored from my back up and all has been running flawlessly like my first 3GS under 3.1.2., well the occasional wifi issue still pops up but not nearly as it did before.

I think I'm going to hold off updating until I feel more comfortable that I'm not going to run into the same issues as others in this thread. Even though there are possible solutions, still seems like a hit and a miss for some. Knowing my luck, I'll fall under the "nothing works for me" category again. iOS 4.0 update just put a huge doubt in my mind, and I don't want to go through another few months of constant frustration. My phone is running as it should, so I'll leave well enough alone this time. lol

I am having some seriously bizarre issues with my battery, some of the following is happening -

- Phantom Usage, I tested over night with 0 minutes usage, 100% charged, morning after 9 hours it had 1 hour 10 minutes usage and down to 87%

- Very fast charging, went from 60% to 90% in about 15 minutes, then to 100% took the normal time, feels as if the battery is being read completely wrong.

- Related to above, after restarting the phone, my battery dropped from 98% to 65%... as if my battery never actually charged before, but thought it was 100%?

I am now going to restore to new, and hope it works better

Ashin wrote:
I am having some seriously bizarre issues with my battery, some of the following is happening -

- Phantom Usage, I tested over night with 0 minutes usage, 100% charged, morning after 9 hours it had 1 hour 10 minutes usage and down to 87%

If you have Push email or Notifications or background apps they can use data when the phone is idle. However, it can also be email responding to phantom activesync requests. There is a fix for this (see below) if no mail is being retrieved.

- Very fast charging, went from 60% to 90% in about 15 minutes, then to 100% took the normal time, feels as if the battery is being read completely wrong.

This is most likely a battery gauge calibration problem. To fix it fully charge the phone, then fully discharge it until it turns off and does not restart. Then charge again for 4 hours.

- Related to above, after restarting the phone, my battery dropped from 98% to 65%... as if my battery never actually charged before, but thought it was 100%?

Same battery gauge problem.

I am now going to restore to new, and hope it works better

Here's the full diagnostic procedure. Stop when you get to one that fixes it. After each step reboot the phone (hold HOME and SLEEP until an Apple logo appears, ignoring "Slide to power off"):

1. Settings/General/Reset - Reset network settings (you will lose WiFi passwords, but nothing else)

2. Settings/General/Reset - Reset all settings (you will need to reset some additional settings, but will not lose data)

3. If you have Push email accounts: Settings/Mail,Contacts,Calendar - tap on the account name and switch it off (the account, not Push). Open the email app; verify the account is gone (and let the mail app know it is). After rebooting, go back to Settings and turn the account back on. Wait an hour before testing to give it time to sync back to the server.

4. Turn off Notifications in Settings. Test for a day. If the problem has gone away you have an app that is using data when it shouldn't be.

5. If you have EVER launched Game Center go to Settings/General/Restrictions and disable Multiplayer games. You will have to set a passcode to do this; DO NOT FORGET IT.

6. Look at the apps currently in the quick launch bar. When on the Home screen double-press HOME. tap and hold any app so "-" signs appear. Kill any apps that might use background such as Facebook, Skype, Yahoo, music streaming apps, etc.

7. If you have gotten this far and not fixed it you probably need to restore as New.

Now I have something else that worries me.
It's 1 day and 11 hours since the last full charge. Usage time shows 6h, 10 minutes and battery is still 41%.
Usually my battery goes down after 6 hours of usage.
After the last full charge I switch the mail app off and the battery life is significantly increased.
I have impresion that the usage time was about 4,5 hours, not 6 hours (maybe it's mistaken)
So either battery life is increased now or it's the metadata glitch you were talking about.
Do you think this is a problem or it's temporary condition?
Thanks for all you support and help

I believe that deffenetly something is wring with the usage time counter.
After 15min using the phone it's shows 55 minutes if usage time.

Shell I use the phone until it's empty completely and then to charge it fully?
Do you believe this metadata could disappear?
Thanks

I had the same problem of battery drain with 4.2 on my Iphone 3gs but after following the instruction here to reset my network settings this solved it for me. Thanks to all those who put this information on the forum.