Edit// Well, looks like I posted this a few hours too late. Apple has released iOS 5.0.1 which fixes the battery issues, amongst other things.
2011.11.21 update: It’s been about 10 days since iOS 5.0.1 was released. I haven’t gotten the exact statistics (although it’s kinda late to find out the pre-iOS 5 stats anyway) but even with the update, the battery still seems to run out faster than it used to. On occasion the phone will shut itself down at ~10% too, so I guess there are still problems with either the OS or the apps. Well, if the apps aren’t optimized for iOS 5 by now it’ll probably take a long time, if ever.
2011.12.03 update: Another update. Even with 5.0.1 the battery definitely drains faster than it used to. In the past my battery could last 1.5 to 2 days before requiring a charge, but now I have to charge it every day (assuming I only use it for messaging, if at all). As mentioned, it still shuts down by itself on occasion, even though the battery is still at 10-15%. I made sure there weren’t apps running in the background too, so it doesn’t seem to be an app-related problem. I suppose with the 200+ new features the battery life naturally takes a hit. So if you haven’t updated to iOS 5 for some reason or other, you might want to consider giving it a miss if you can live without the new features.
It’s been about a month since iOS5 was out, but I only updated my iPhone in the last few weeks since I was reformatting my computer. It’s been about a month already, but Apple has yet to solve the battery drain problem that some (most/all?) people have been encountering. Since the iPhone 4S comes with iOS5 installed it also has the same problems, but it exists on other platforms too.
Besides the (way) faster drain, I myself had my iPhone 3GS shut itself down at ~16% capacity, whereas in the past it would still work at 2-3%. Haven’t really heard of this happening to other users though, so maybe it’s the platform. Gave me a whole lot of trouble when I was going to my friend’s house and had to find a place to charge it so I could call him to meet me. Supposedly, there’ll be a fix within the next few weeks though. But before that happens, here’s a few tips to reduce the battery drain (it’s improved for me after I took the following steps, but it still seems to be draining faster than it used to).
Disclaimer: I’m not the most hardware/technically proficient person so the solutions I listed are based on what I found on the Internet.
Recalibrate your battery
- Drain your battery until it shuts itself down. Additionally you might want to leave it for a while as I notice the battery somehow still drains if you shut down your phone manually and turn it on again later.
- Charge it to 100%.
- Do a hard reset by holding the lock and home button (until the Apple logo appears).
- On a related note, you might also want to reset your network settings (Settings → General → Reset Network Settings)
- Disable Location Services for any apps that won’t be needing it.
- Watch out for the icon which will show if there’s any app that’s using the service unnecessarily/frequently.
- Also, disable Location Services for the system. What you will likely only need are the first 2. Check Gizmondo’s article for information on the services.
- Apparently in iPhone 4/4S (at least, it’s not the case for my 3GS), the ‘Setting Time Zone’ feature uses the location service rather frequently, so watch out that.
- Turn off syncing for Contacts, Calendars and Reminders if you don’t need them.
- Apparently syncing for Exchange mail accounts seem to contribute more to the battery drain, although that may not be a specific iOS5 problem.
- A general tip (even if you’re not using iOS5) would be to disable Push and set Fetch to a lower frequency, or even to Manual.
iCloud/iTunes Wireless Sync
- Turn off any iCloud sync features that you don’t need (or just turn off all of them).
- Same goes for iTunes Wireless Sync, although technically it should only affect the battery if you’re actively syncing.
- At least, until Apple officially fixes the problem.