Apple 's claim that the Apple Watch Series 11 offers 24 hours of battery life has sparked controversy, as a closer look at Apple's testing data reveals that the increase from the Series 10's 18-hour estimate is primarily due to changes in testing methodology, rather than a significant change in hardware.
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Apple says the Apple Watch Series 11 can last up to 24 hours on a single charge, a notable increase over the Series 10's 18-hour claim, which has been the company's published standard since the original Apple Watch was released in 2015.
As noted by a user on the MacRumors forums, the main difference between the two test scenarios in Apple's official documentation is the inclusion of sleep tracking in the Apple Watch Series 11 rating. Apple states that the 24-hour figure is based on 300 time checks, 90 notifications, 15 minutes of app use, a 60-minute workout with music playback, and six hours of sleep tracking. The comparable Series 10 test lists the same parameters but does not include sleep tracking.
While Apple doesn't break down the exact battery consumption of each activity, sleep tracking is generally a low-power feature, allowing older Apple Watch models to be worn all night without fully depleting their charge.
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Many users have pointed out that Apple Watches have long exceeded the company's stated 18-hour battery life in real-world use, with most users comfortably managing to track all night. This suggests that the six-hour increase is largely due to the addition of sleep tracking to Apple's official scenario, rather than a significant increase in actual battery life.
Apple also publishes battery life estimates for Low Power Mode, which further show only modest changes. The Series 11 is rated for 38 hours of battery life in Low Power Mode, compared to the Series 10's 36-hour estimate. Here, Apple's footnotes indicate that the Series 11's testing used lower activity levels: 530 time checks, 160 notifications, and 26 minutes of app use, compared to 600 time checks, 180 notifications, and 30 minutes of app use for the Series 10.
Both tests involved a 60-minute workout and six hours of sleep tracking. The reduced activity assumptions make it difficult to directly compare the numbers, but even Apple's own calculation only achieves an improvement of about 8%.
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The Apple Watch Series 11 also features slightly larger batteries across its range of case sizes. According to official safety documentation, battery capacities for Series 11 models range from 1,245 to 1,403 watt-hours, depending on case size, compared to 1,118 to 1,266 watt-hours for Series 10 models. That represents a capacity increase of about 7% to 10%, much less than the 33% jump implied by Apple's move from an 18-hour to a 24-hour claim.
