Actually in my experience, leaving Wifi on saves the battery, compared to telco network. Wifi seems to be more power-efficient than 3G or LTE. Of course, if yo

Actually in my experience, leaving Wifi on saves the battery, compared to telco network. Wifi seems to be more power-efficient than 3G or LTE. Of course, if you want a week on the battery, you must have data off, both wifi and mobile.