Unwanted battery drain is a common issue on almost every Android device. In most situations, you can easily find the battery guzzling culprit: network mode. 3G or LTE are useful because of fast Internet, but most of the time, we don’t need them—especially in a location with WiFi. Manually disabling them is an option, but not the most convenient one. Some might mention Tasker or Llama, and you are right. However, these applications are far from being easy to use for new users.
Xposed modules are extremely popular because they don’t require custom firmware to apply some changes. One such module was developed by XDA Senior Member veagles. Intelli3G manages your Android device’s connections and disables 3G when you don’t need it. Connection mode will be changed whilst your device is in WiFi range or in your pocket. Of course, when you need a fast Internet, 3G will be automatically activated after lighting up the screen. Only the Google Nexus 4 is officially supported at the moment, but some users have reported that it works flawlessly on the Nexus 5 and some Samsung Galaxy devices. There is a chance that other devices should work as well. As it’s an Xposed module, your phone must be rooted and have Xposed Framework installed.
If you suffer poor battery performance and would like to improve it, make your way to the application thread and give it a shot. Don’t forget to report back if Intelli3G works on your device.
[Big thanks to XDA Senior Member Robin>Hood for the tip!]