Apple Watch Ultra Features 76% Larger Battery Than Series 8

The Apple Watch Ultra features a 76% larger battery compared to the 45mm Series 8, according to newly uncovered specifications in a Chinese certification database.

The certification, spotted by MySmartPrice, reveals that the Apple Watch Ultra features a 542mAh battery. The 45mm Apple Watch Series 8 features a 308mAh battery, representing a 76% increase in battery size for the Apple Watch Ultra compared to the previous largest Apple Watch.

The documents also confirm that alongside the Apple Watch Series 8 featuring the same CPU as the Series 6 and 7, the new Apple Watch also shares the same battery size. The 41mm Series 8 features a battery capacity of 282mAh, while the Series 7 features a 284mAh battery. The minimal difference in battery size is unlikely to be noticeable. The 45mm Series 8 also shares the same battery size as the 45mm Series 7.

With the Apple Watch Series 8, Apple promises the same all-day battery life as previous generation models. With the Apple Watch Ultra, Apple says that users can expect up to 36 hours of normal use and up to 60 hours with Low Power mode enabled, offering the longest battery life ever in an Apple Watch.

Low Power Mode, which is available on all Apple Watch models supported by watchOS 9, extends battery life by disabling features such as background app refresh, the always-on display, background blood oxygen measurements, and more.