Ultra-Endurance GPS Watch with Exceptional Battery Life & Barometer. Three predefined battery modes Performance, Endurance and Ultra deliver from 25 hours to up to 120 hours of recording time with GPS tracking on. Suunto 9 uses smart reminders based on your activity history to help ensure you are fully charged for your next outing. If the watch notices you are running low on battery during an exercise, it will automatically suggest changing to a different battery mode. Never Worry About Running Out of Battery.