****Battery life has been measured against Sony Mobile Communications AB’s smartphone usage profile, defined in September 2014 to represent the typical smartphone user’s active condition, including but not limited to a range of usage scenarios (calling, texting, web browsing, social networking, game playing, music listening, picture taking, picture browsing, online video watching, video recording and playback).
*****The Xperia Z5 Premium Dual is waterproof and protected against dust, so don’t worry if you get caught in the rain or want to wash off dirt under a tap, but remember: all ports and attached covers should be firmly closed. You should not put the device completely underwater or expose it to seawater, salt water, chlorinated water or liquids such as drinks. Abuse and improper use of device will invalidate warranty. The device has Ingress Protection rating IP65/68. For more info see www.sonymobile.com/waterproof. Note the Xperia Z5 Premium Dual has a capless USB port to connect and charge. The USB port needs to be completely dry before charging.
Source: http://www.sonymobile.com/global-en/products/phones/xperia-z5-premium-dual/#specifications