Power Manager Settings
Hold MENU, and select Power Manager.
Battery Saver: Allows you to customize system settings to extend battery life in watch mode (Customizing the Battery Saver Feature).
Power Modes: Allows you to customize system settings, activity settings, and GPS settings to extend battery life during an activity (Customizing Power Modes).
Battery Percentage: Displays remaining battery life as a percentage.
Battery Estimates: Displays remaining battery life as an estimated number of days or hours.