I've searched through many forums but haven't really found an answer to an issue I'm having after making the change to ICS (4.0.3). I'm will Bell (in Calgary) and two weeks ago, I made the change from Gingerbread to Ice Cream Sandwich through Kies. Since then, the battery usage when I'm connected via wi-fi is very high (compared to what it was with Gingerbread). I did a test yesterday by fully charging the battery and then turning on only wi-fi (where it connected to my home router). I did not use the phone at all (I went to bed). When I woke at about 8:00 am, I turned off the wi-fi connection and turned on the 3G/4G connection (I don't know if it was on 3G or 4G, but I assume 4G). Again, I did nothing on the phone until about noon. See image below which shows the battery usage.



With Wi-fi connected, I could maybe get 12-14 hours out of the battery (with no phone usage) whereas with 3G/4G, I could easily get 24 hours or more. I thought Wi-fi used less battery than 3G/4G?? And while I don't really mind using 3G/4G for better battery life, it does eat away at my data plan.

As far as I'm aware, I never had this issue before the upgrade to ICS, so I'm wondering if Gingerbread had different settings for the Wi-fi connection. Here are my current Wi-fi settings, which I set after the switch to ICS:



I have factory reset the phone after the ICS update (I did that last weekend about one week after the change to ICS). If anyone can educate me on what I should expect with Wi-fi vs. 3G/4G with Ice Cream Sandwich, I would appreciate it! Until then, I'm going to change the setting to let Wi-fi disconnect when the phone sleeps and see what impact that has on battery life. Regardless, I still believe the Wi-fi should use less battery than 3G/4G. (How do I tell if I'm connected 3G vs. 4G?)

Thanks,
ATE