Okay, I fiddled with my phone and here is what I have come up with:
1. Keeping wifi off all day has enabled me to retain a good charging battery (unplugged at 100% this morning around 7am and at 2:15pm I am still at 77% with light usage, texting, checking facebook, checking gmail/work emails, and a few calls). Now, I have my mobile network set to 3G all the time and not 4G.
2. Before my phone times out or I time it out myself, I long-press the home button and clear out the running apps in task manager.
3. I have a black wallpaper (no live wallpaper), a few widgets, and am using the replacement home launcher "Holo Launcher."
4. My display is set to about 25% at normal density.
I should mention that before all of this, I did perform a factory reset to clear out all the old stuff and whatever else was in there to start from scratch. Tonight, I am going to perform the battery method (turn off, charge to 100, remove battery while plugged in, leave battery off for 5 minutes, replace, and reboot) to see if that helps any. Overall, this really hasn't been that much of an issue for me with the OTA. Sure, my battery life at first was horrible but with a few suggestions from the forums, reading others, and playing around with some settings, it is getting much better. I will report back tomorrow to see how the battery method worked out. Good luck to everyone else.
I upgraded to ICS on Tuesday morning and have had the same issues that the rest of you have discussed. There are two things that I would add that hopefully will give you some hope!
1. In reading the posts on the European rollout of ICS, it sounded like after a week the battery use would stabilize and most people reported that it was going back to their normal battery use.
2. I was reluctant to do a factory reset because of having to reload all my apps, so I went and cleared the cache as a last ditch help before the factory reset. I did that last night and today my battery life has been back to pre ICS usage. I'm using about 5% per hour which means I can get from morning to bedtime on one charge, which is what I was using before.
So I don't know if it was 1 or 2 or a combination of both, but hopefully you are all seeing some improvements as we get away from the install. What bothers me most in all of this is that Spring/Samsung have not had any idea. The whole Swype issue should have been texted out to every number that downloaded ICS. If they have it pre recorded on their help line, just tell us! I can't believe that they didn't test the rollout and get some of the same issues.
Well, and I need to update my status. I really don't have the same battery life that I used to have - it's close, but it's just not quite there, even with all the extra steps I'm having to take. I hope you're right Treg and it does get better soon, because how it's going right now is disappointing.
I agree, this whole process has been very disappointing and has me seriously considering an iPhone and Verizon when my contract is up. I've been with sprint for 14 years and you think I would have learned by now.
I have literally spent a week researching different techniques to really restore battery life to the way it was in gb. And nothing has worked now granted if I were to turn off a bunch of services I could probably get it back but I don't want too and shouldn't have too this was not needed in gb. From my readings it actually looks like these issues are wide spread and effecting other s2 devices across the globe which really makes me believe the issues lie with how samsung implemented ics. I did not have any of these problems when I upgraded my evo 3d to ics. So I really don't thick its Google's fault or the excuses people make when they say ics just runs more services.
Well, today has been much better and I think my battery life is starting to improve. I did perform the battery suggestion (turn off, charge to 100%, pull battery while plugged in, wait 5 min, put back battery, and restart). This morning after I woke up, did the pull and 5 minute wait, my battery life has been so much better than before. Granted, when in wifi the battery juice is eaten up quickly so I have one toggled it on when needed and right away turn it off after done. At 7:15am, I had a 99% full battery and now at 9:15pm, I am sitting right at 56%. This includes mobile network set to 3G, receiving emails constantly throughout the day (over 30 or so), a couple of times on facebook (with wifi once and with 3G the other), sending/receiving text and mms messages, playing around with a few apps, and several phone calls. Now, what I have been doing right before I am finished with using my phone is long-pressing the home button to get to the task manager and clear out the running apps. I am still using the Holo Launcher in place of the TW launcher. The only thing I have noticed is that there is still a little lag, at times, when swiping through the homescreen between screens and in the app drawer. It's not much of a big deal but it feels less responsive than with GB. I know each and everyone of us use our phones differently and we are not going to all get the same results but from what I have been experiencing and performing, so far the battery life seems to be improving slowly. Good luck to everyone!
[SOLVED] (for me anyways)
I also experienced a dramatic loss in battery life after the ICS update. After reading much online about others experiences and after doing some testing of my own I finally have my battery life back to normal... even better than before when I was on Gingerbread. However, it is somewhat of a pain to manage. I discovered 4 things affecting my battery life... WiFi, 4G Wimax, and 2 apps (Juice Defender and InstaMapper GPS Tracker). I installed CPU Spy and BetterBatteryStats to moniter what was happening to my phone. In a nutshell WiFi and 4G Wimax keep the phone from going into deep sleep. So I disable WiFi and 4G and enable 3G when not using the phone. (Menu... Settings... toggle both WiFi & 4G off. Menu... Settings... More... Mobile Networks... check 3G Data) That would have been enough except for the 2 rogue apps I mention above. Juice Defender and InstaMapper GPS Tracker seem to enable WiFi and 4G even when I manually disable these. So I uninstalled these apps. (There may be other apps that you are using that also disregard your manual settings and enable WiFi and 4G.) When not on WiFi nor 4G and only using 3G, the phone does go into deep sleep and stay there until I wake it. So you can see it is manageable, but a pain or at least slight inconvenience. With moderate usage, including turning on/off my WiFi and 4G throughout the day, I have 20+ hours of usable battery life. I hope this helps.
I was having the same battery life problems, and then today, I got a data usage warning that indicates the Mail program (not Gmail) has used 1.98 GB of data, in 6 days!!! So I think I found the culprit, but I can't figure out why it's happening or how to stop it, short of just not using the mail program. I might try to delete and re-establish the account and see if that does the trick.