Apple Watch Ultra 4 delivers up to 50 hours of battery life and 84 hours in Low Power Mode

Apple Watch Ultra 4 pushes battery life beyond the previous generation, with Apple rating its new rugged smartwatch for up to 50 hours of everyday use.

That takes the Ultra beyond the two-day mark without requiring Low Power Mode, while switching the feature on can extend battery life to as much as 84 hours.

Apple is also targeting endurance athletes with two dedicated extended workout modes, allowing the watch to continue collecting workout data over significantly longer periods.

Extended Workout mode provides up to 25 hours of outdoor workout tracking with GPS and heart-rate readings. Apple says that represents a 25 percent improvement over the previous generation.

For particularly long events, Max Extended Workout mode can track outdoor runs, walks and hikes for up to 45 hours. GPS readings continue to be taken every second, although some workout features and metrics are disabled to conserve power.

Apple specifically says the 45-hour mode should typically provide enough battery life to complete a 100-mile race, giving Ultra 4 a stronger proposition for ultramarathon runners and other endurance athletes.

Charging has been improved at the same time. A 15-minute charge can add up to 18 hours of battery life, reducing the amount of time users need to leave the watch off their wrist.

The battery improvements arrive alongside Apple’s S11 chip and new Health Sensing System, which actually increases the frequency at which Ultra 4 collects some health data. Heart rate is measured every five seconds throughout the day and HRV measurements are taken substantially more often.

Apple Watch Ultra 4 is available to pre-order now, with availability beginning Friday, September 18. It starts at $799 in the United States and comes in natural and black titanium.