I noticed that my "Android OS" was keeping my phone awake for like 4 hours in a 16 hour period. I have BetterBatteryStats installed and checked the kernel wakelocks. I was getting a "wlan_rx_wake" wakelock which was causing 92% of my kernel wake locks. After some googling, it turns out that this is related to the phone responding to wireless router DHCP queries, and the simple way to resolve it is to assign a static IP address to your phone. Luckily my router allows me to use static IPs in conjunction with DHCP, so I didn't have to reconfigure every device on my network. The stay awake time now is less than half an hour for Android OS and it's only using 6% battery, when it was using like 20+% before. It's a very noticeable difference for such an easy change! --- Now I just want to figure out how to stop cell standby using so much battery! It's currently using 2% less battery than the screen which has been on for two hours. That's insane I suspect we'll have to root and install a custom radio or wait until Samsung pulls their finger out!