[Sprint Samsung Galaxy S III] castle_bravo:
Write up for 3G always on vs little to no 3G usage on slimmed deodexed stock 4.1.1 using KT747 on a stock battery:

I attempted to use the phone equally during both runs. Surfed the web, texted, called, basically used the phone normally. I did however go in to recovery during my no 3G use and made a back up and flashed some files. To make things fair I did the same with all 3G use. (actually accidentally deleted my backups folder DOH! So I had to do it.) These are the results.

With no 3G use I used Wi-Fi when needed. I kept the radios off the whole time unless needed to check xda or surf the web or things of this nature. I dont have bookface and I don't twat so no information on that. When I was not within a Wi-Fi area I turned the 3G on for exactly the only amount of time needed, I tried to keep this to a minimum since it was a benchmark. Below you will find my battery stats with usage. Pretty outstanding. Now this is no game playing and using the phone as a phone. This means talking, texting, some email, and some internet browsing. I deleted screen time but it is a few posts back, I believe it was 3.5 hours

With 3G on all the time I saw HALF the battery life as with NO 3G. IMPORTANT: I was in a very good connection area which contributed to the great battery stats even with 3G enabled. It is important to note that at my place of occupation I have extremely poor reception and I will see half of these numbers. 12 hours battery life with 1.5 hours screen time when 3G is enabled the whole time. 1 day and 3 hours is great IMO but I will keep 3G off unless I need it, and when I am home I will be using Wi-Fi.

As you look at the picture and the long period of little battery drain you will notice the mobile network signal bar at the bottom is black. I believe the phone shuts down your connection and periodically checks again when it is in deep sleep (Don't know the periodicity). I drained 7% battery in 7 hours of screen off time while 3g was enabled with a good connection. With 3G off I did not see even a single percentage drop. Notice the difference in percentages between the first and second picture for Android System. Bam_dmux kernel wakelock was noticeably higher while 3G enabled which I believe Kenny mentioned earlier (Sorry if I credited the wrong person-will correct if needed) The only thing I did differently was the 3G use. All sync features are disabled. Below are my settings.

Final write up:

Battery drain with 3G enabled is noticeably more than with 3G disabled. However, I can not duplicate earlier reports of bad battery drain due to 3G use. I myself even reported this problem. It is my opinion that if you are in a poor connection area to disable 3G until you need it because it will KILL your battery, but if your connection is solid I wouldn't worry about it. 3G disabled while phone screen is off overnight did not produce even a single percentage loss from 100%. It was mentioned earlier but you should charge your phone an hour or two past the point in which it says fully charged. This does actually make a difference. This kernel is bad ass and with the numerous tweaks available by both freecharlesmanson, mw86, and your own tweaking (see above) you can make this phone last 2 days on a full charge using a stock battery with what I call "normal" usage.