The Xperia Z1 offers a massive 3,000mAh battery life. Sony gives you the access to the phone's power management tools including Stamina mode to disable data when the screen is off and a low battery mode to conserve power when you have reached critical battery life levels.
On full charge and in general use playing games, browsing the web, and using Twitter and Facebook, you can get through a day comfortably. That's without tapping into the stamina and low battery modes. You can actually get a around a day and a half of proper use, if you are not using it excessively.
