I eagerly started my download of iOS 5 20 minutes after it went live… apparently a few other people were doing the same thing. Over 4 hours later it was installed. I played with the features for a while and was overall impressed with photo-stream, iCloud and Notification Centre.
I put my iPhone 4 on charge that night and my fiancé didn’t bother as hers was at 95% battery and normally lasted her 2 days anyhow. The next morning I sat in bed and checked my twitter, Facebook and the news and thought it a bit strange how my battery had already gone down to 89% during that 10 mins of usage. My fiancé’s iPhone 4 was on 4% !!!
After having been live for a few days it seems we’re not the only ones with this problem. After reading some infuriating articles suggesting I
turn off notifications
or
disable location services
or
disable iMessage
or anything else that makes the iPhone great I started to do a little digging and found that deep in the menus were some items that perhaps helped my battery to last longer, I also did a lot of forum reading and have summarised my findings below.
Bear in mind this is obviously buggy behaviour and until there is an official fix I’ve implemented the “fixes” below as a temporary countermeasure: -
Time Zone
Buried inside Settings > Location Services > (scroll to bottom and find) System Services
Firstly you’ll notice that by default the “Status Bar Icon” is Off. This means than whenever your iOS 5 device is performing on of the location functions above that it neglects to tell you about it on your main status bar (with your time etc).
Secondly you may notice that “Setting Time Zone” has a coloured location-symbol next to it permanently which means it’s always live. Obviously if it’s always getting your location then that’s quite a hit on battery life but also; do you really need your phone to constantly be checking which time-zone you’re in? I opted for not and set this to Off.
Notifications
I’m not sure whether this has had a large impact on my battery’s performance but it’s advised that you go into Settings > Notifications and switch off any notifications that you don’t actively need. There are plenty of Apps that I have installed on my device that simply do not need notifications yet seem to want to register with the Notification Centre and be eligible for push notifications.
Usage Information
Your iPhone is sat there sending anonymous Diagnostic and Usage Data to Apple… when it wants… using up your battery life.
For this one you’ll need to go into Settings > General > About > (scroll to bottom) Diagnostic & Usage and then chose the setting “Don’t Send”.
iCloud
iCloud is great and all but it does generate a lot of network data which again; uses battery. For me I don’t need to sync my Mail, Contacts or Calendar into iCloud as they originate on an Exchange server so why sync them to iCloud? Also I don’t use the Safari web browser so do I need to sync my Bookmarks with the cloud? This is much like with the Notification Centre; only sync and use the features that you need and/or want!
Ping
This is a social-networking experience (or attempt at) from Apple within iTunes. I don’t know if this was included in the previous iOS releases but apparently disabling it has some negative impact on battery so if you weren’t aware of its existence or aren’t using it then Settings > General > Restrictions > Enable Restriction (and set a restrictions pass-code > Ping : Off.
Network Settings (the most effective change yet!)
I read this one a few times on various sites and refused to believe that it could make the slightest bit of difference. That was until I was getting sufficiently frustrated that I decided to go for it. BIG difference! Before you go ahead, there is one disadvantage: your iPhone will forget all the WiFi networks it has previously joined and you must provide the security keys again.
To perform this operation head to Settings > General > Reset > Reset Network Settings. You’ll need to confirm that you really want to do this and then your iPhone will reboot. Don’t forget to re-join your WiFi networks 
Hopefully if you perform these steps you’ll grab back some ever-useful battery life without limiting functionality.
Let me know how you get on or if you have any suggestions and if you have 2 seconds; answer the poll below:
