There is definitely something wrong with the Wifi settings. For example, when you are in the "Advanced Wifi" section, you can either check or uncheck "Notify me when an open network is available." Even if you have that unchecked, the wifi is still scanning for an open network which is causing that pitiful battery drain. I was just on that setting for maybe a minute or two and my battery quickly went from 96% to 94%. For now, I am just turing off wifi and using it only when needed. This is one of the culprits that needs to be addressed and resolved by Sprint.
shoot..i forgot about that..go into settings-wireless and networks-mobile networks and towards the bottom you guys should have something like "automatic connections"..the OG EVO got it in one of their updates so im sure you guys have it now too..if its there (dont have an SII to look myself) uncheck it and see if there are any improvements on battery.
let me know if it IS there or not..thanks
drat...thought i was onto something here..i'll have to get back to you guys lol..
Hey, it was a great suggestion though...thank you for the input. I guess we will just have to keep brainstorming or see what comes of this. Despite the minor inconveniences, I am not going to let this affect my life. Besides, it's just a phone and I will work around this untiil something happens. I know that many people do rely on their phones for business, personal life, and such so I can understand the frustration they may be facing right now. For now, I am simply just keeping wifi off until I need to use it. Good luck to everyone else and let's keep seeing what we can come up with to help get a fix on our phones. =-)
[SOLVED] (for me anyways)
BATTERY DRAIN ON ICS
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.
FYI, I just called Sprint to inqure about my call on 7/16 concerning low battery life with wifi. I was told Sprint is waiting on Samsung to provide a fix (software update) for the problems with the ICS roll out. I then called Samsung and they said they haven't heard of any battery life problems with the ICS update. So, I don't have much confidence for an official fix any time soon.