The battery life indication that you see in the exercise start display or in the battery mode settings menu is an estimate of how long the battery of your watch will last during exercise. The value is always rounded down, which means that e.g. 20.9 or 20.1 hours of calculated battery life will be rounded down to 20 hours.
The following settings and conditions may impact the actual battery life:
- GPS conditions. A low number of satellites and surroundings with obstructions like trees, buildings, mountains, etc. impact the GPS signal strength. Thus, the GPS will consume more power to track your exercise.
- Backlight set to ON. To save battery life and keep it according to the estimations, keep the Backlight toggle to normal (toggle is grey) in the Options menu below the exercise start display.
- Browsing through data displays during exercise. When switching between displays, the display backlight is on and consumes battery. To save battery life, keep display browsing to a minimum.
- Using the navigation display during exercise. When using this display, the GPS accuracy is switched to Best to provide the best possible track for navigating. This means that the GPS setting of the battery mode will be overridden as long as you are in the navigation display. When exiting this display, the GPS accuracy will be switched back to the GPS accuracy defined in the battery mode.
- To save extra battery life, use a chest HR belt e.g. Suunto Smart Sensor to track your heart rate.