With Apple Watch orders due to begin arriving in less than a day for early buyers, we take a look at battery life. Apple Watch users will want to wear their Watches all day long, so Apple made sure they gave it a battery that lasts all day, too. Apple’s goal for battery life was 18 hours after an overnight charge, factoring in things like checking the time, receiving notifications, using apps, and doing a 30-minute workout. And because everyone will use Apple Watch differently, Apple tested several other metrics as well.
Note that the following Apple Watch battery performance claims are based on test results from the 38mm Apple Watch. A 42mm Apple Watch typically experiences longer battery life.
All-Day Battery Life: Up to 18 hours
Testing conducted by Apple in March 2015 using preproduction Apple Watch and software paired with an iPhone using preproduction software. All-day battery life is based on 18 hours with the following use: 90 time checks, 90 notifications, 45 minutes of app use, and a 30-minute workout with music playback from Apple Watch via Bluetooth, over the course of 18 hours
Talk Time Test: Up to 3 hours
Testing conducted by Apple in March 2015 using preproduction Apple Watch and software paired with an iPhone using preproduction software with a call placed from Apple Watch.
Audio Playback Test: Up to 6.5 hours
Testing conducted by Apple in March 2015 using preproduction Apple Watch and software paired with an iPhone using preproduction software with music playback from Apple Watch via Bluetooth.
Workout Test: Up to 6.5 hours
Testing conducted by Apple in March 2015 using preproduction Apple Watch and software paired with an iPhone using preproduction software with a workout session active and the heart rate sensor on.
Watch Test: Up to 48 hours
Testing conducted by Apple in March 2015 using preproduction Apple Watch and software paired with an iPhone using preproduction software with 5 time checks (4 seconds each) per hour.
Power Reserve: Up to 72 hours
If your battery gets too low, Apple Watch automatically switches into Power Reserve mode so you can continue to see the time for up to 72 hours. Testing conducted by Apple in March 2015 using preproduction Apple Watch and software with 4 time checks (4 seconds each) per hour.
Charge Time: About 1.5 hours to 80%; About 2.5 hours to 100%
Testing conducted by Apple in March 2015 using preproduction Apple Watch and software paired with an iPhone using preproduction software. Charge times are from 0% to 80% and from 0% to 100% using the included MagSafe inductive charger. Charge time varies with environmental factors; actual results will vary.
Battery life varies by use, configuration, and many other factors; actual results will vary.
Source: Apple Inc.