This comes shortly after CEO Tim Cook confirmed that the wearable's battery should last for 18 hours in general use.
In the breakdown, Apple gives us a detailed view of how it landed on the 18-hour figure:
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. Battery life varies by use, configuration, and many other factors; actual results will vary.
For specific use scenarios, Apple says that the watch should hold up for up to 6.5 hours with continuous music streaming through Bluetooth, 3 hours of talk time for calls placed through the watch, and up to 7 hours in workout mode with the heart rate sensor active. Additionally, if you simply use the watch for checking the time, Apple says you should net up to 48 hours of use with 5 time checks per hour.
Finally, if you're Apple Watch gets low on power, it will automatically switch into Power Reserve mode and should last up to 72 hours while periodically checking the time. Once the battery does die, however, Apple notes that it should charge up to 80 percent in about an hour and a half, with a full charge taking two and a half hours.
Apple notes that all of these test results are based on the 38mm model, noting that the 42mm Apple Watch typically lasts a bit longer on a charge.
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