Upgraded to iPhone OS 3.0 and running out of battery fast?

In: iPhone

22 Jun 2009

After upgrading my girlfriend’s iPhone 3G to OS 3.0 recently, I noticed that the iPhone’s battery was getting depleted really quickly. I’d left it overnight with Wifi, 3G, Bluetooth, Push Notifications all off, and the battery went from 80% to a jaw-dropping OMGWTFBBQ 10%.

I attributed it to the recent jailbreak (I’ve already removed the jailbreak trying to figure out this problem) at first. I only realized something was really wrong when the iPhone’s battery started draining while it was charging via USB!

Looking around on teh interwebs, I managed to solve it (easily!) by following the suggestions from this thread at the Apple support forums. Here’s what worked for me:

  1. Go to Settings on your iPhone.
  2. Turn Notifications off. I’m not sure if this is necessary but did so just in case.
  3. Go to Mail, Contacts, Calendars and delete all your accounts (I deleted even Calendar accounts just in case). You may want to write down or backup your account settings first.
  4. Go to Fetch New Data (also in the same Mail, Contacts, Calendars settings) and make sure Push is Off.
  5. It’s probably not necessary but you may want to restart your iPhone (power it on and off) here.
  6. Add back all your accounts. You can turn Push back on Fetch New Data now.
  7. You can also turn Notifications back on if you wish.

It seems like the iPhone 3.0 OS update has a bug where email accounts with active push notifications were set to keep fetching new email even if push is turned off explicitly. Hopefully this post will help solve your battery problems, if not, you’ve gotta keep looking – the Apple iPhone Support forums is a good place to start.

6 Responses to Upgraded to iPhone OS 3.0 and running out of battery fast?


Koen Van der Auwera

June 22nd, 2009 at 11pm

mm, on my side, I was/am under the impression I got a better battery life after the upgrade to 3.0


Chu Yeow

June 23rd, 2009 at 12am

Me too! I’ve been hearing complaints though that battery life actually got worse for most non-iPhone 3G S owners. I guess it varies.

Good news for me is that I’m getting an iPhone 3G S of my own when it comes out in Singapore.



June 23rd, 2009 at 1am

I had the exact same issue. I too blamed my jailbreak. I had figured that it was something like SBSettings churning the CPU. I re-jailbroke my iPhone (3G) but did not install any Cydia apps.

At around the same time, for different reasons (auto-lock issue), I reset my mail settings.

I no longer have the battery issue.

I might even work up the nerve to install SBSettings later today…



September 8th, 2009 at 3am

I’ve seen this problem a few times and I dont think it has anything to do with notifications or push being activated. For some reason if you’ve upgraded from 2.x to 3.x and chose to restore your iPhone from a back up instead of a fresh install the batterey problem seems to pop up. I had the same issue and all I had to do was back up my contacts then restore the iphone, then when it asks if you would like to set up as a new iphone chooses that option. This will also resolve the youtube issue if you are using t-mobile and your youtube cant connect to the server.


Chu Yeow

September 8th, 2009 at 8am

Hi James, glad that that worked for you. I managed to solve my battery problem without setting up the iPhone from a fresh install though so YMMV.



January 13th, 2011 at 11pm

THANK YOU SO MUCH!! I just took your advice and did the steps outlined on my phone, and it worked! Before, my battery would go from 100% to 20% in about 2 hours, but last night before I went to bed, my phone was at 100%, and when I woke up this morning, it was at 96%! Thanks again, this was super helpful.

Comment Form