Rob Pegoraro's post on Android | Latest updates on Sulia
Nexus 4 battery-life tip: This phone runs almost exponentially longer on WiFi plus 3G. (But I don't know why.)
Back when I was testing a loaner Nexus 4 phone, I was disappointed by its battery life on 3G (http://sulia.com/channel/android/f/65a7f54e-bf83-4a77-b7cc-e009d65ce46c/). What I didn't know at the time was how much better this phone runs when it's connected to both WiFi and mobile broadband.
It doesn't have to be doing anything--even if left mostly idle, the battery will last much longer on WiFi and 3G than on 3G alone. This improvement, as seen in the typical screen shot above, far exceeds the usual battery benefits I've seen from WiFi.
I have to assume that there's some power-management glitch that Google fixed with WiFi but not 3G. But in the meantime, I enjoy being able to wrap up a day at work and realize that the battery's still over 90 percent charged.