From what I see there are different kinds of battery problems. Some are just caused by apps, but mine is different... My battery has no significant drain, but about 2-4% per hour on idle, this is kind of abnormal, it's like ~20% overnight. I noticed that the battery meter itself is not accurate, i.e. it shows different readings after restarts, so I tried calibrating it as well as resetting the phone, none seems to work so far. I don't know if this issue belongs to hardware or software. Because I checked many Lumia online communities and lots people have similar issue, so hopefully it is just an OS bug that will get fixed in the near future. (The bad news is that both Nokia and MS have said nothing about it...)
How you turn off 3g/4g/wifi ? The only way that comes to my mind is by turning airplane mode on but the phone will be useless. And we don't have the option of choosing between 2g/3g/4g or LTE on AT&T
I read somewhere in this forum where someone did something to his lumia 920 to get impressive battery life. His method was making an outlook email and set it up in wp8. Then, link other email accounts such as yahoo, hotmail and gmail to the outlook account. The reason why he did not use normal gmail setup was because gmail will constantly reading to the server even though it has been closed. I did not fully understand it either but it surely works! Before applying this method, my max battery life as stated in battery info was 16 hours. Surprisingly after doing the outlook method it increase to 1 day and 12 hours. That's a very big difference i must say. Another thing is turn the screen brightness to low. Hope this helps.
I've added a screenshot. Have a look.