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.

apple watch ultra 2
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.

Related Roundup: Apple Watch Ultra 2
Related Forum: Apple Watch

Popular Stories

iPhone 16 Battery Life Feature

iOS 26's New Battery Life Mode Available Only on These iPhone Models

Saturday June 21, 2025 9:02 am PDT by
Last week, we reported that iOS 26 introduces an opt-in Adaptive Power Mode on the iPhone, alongside the existing Low Power Mode. Apple says that Adaptive Power Mode can make "small performance adjustments" when necessary to extend an iPhone's battery life, including slightly lowering the display brightness or allowing some activities to "take a little longer." The full description of...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching in Three Months With These 12 New Features

Saturday June 21, 2025 2:45 pm PDT by
The iPhone 17 Pro and iPhone 17 Pro Max are around three months away, and there are plenty of rumors about the devices from credible sources. Below, we recap key changes rumored for the iPhone 17 Pro models as of June 2025:Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone X...
apple wallet drivers license feature iPhone 15 pro

iPhone Driver's Licenses: These 17 U.S. States Offer Them or Will Later

Thursday June 19, 2025 11:28 am PDT by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Unfortunately, this feature continues to roll out very slowly since it was announced in 2021, with only nine U.S. states and Puerto...
All Screen iPhone 2027 Feature 1

iPhone Reportedly Moving to All-Screen Design in Two Stages

Sunday June 22, 2025 3:58 pm PDT by
Apple has long been working towards an iPhone with an all-screen design, and it might finally achieve the feat in a few more years from now. In his Power On newsletter today, Bloomberg's Mark Gurman said that Apple will shrink the size of the Dynamic Island on new iPhone models released next year. A year after that, he expects Apple to release a redesigned 20th-anniversary iPhone model....
ios 26 call holding

iOS 26 Beta is Hiding a New Ringtone — Here's What It Sounds Like

Thursday June 19, 2025 7:25 pm PDT by
Apple is hiding a new ringtone within iOS 26. The new ringtone is an alternative version of the existing Reflection ringtone, which has been the default ringtone since the iPhone X was released in 2017. It was discovered within the code for the first developer beta of iOS 26, but it remains hidden, so you will not find it in the list of ringtones available in the Settings app for now. It...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching in Three Months With These 12 New Features

Saturday June 14, 2025 5:45 pm PDT by
The iPhone 17 Pro and iPhone 17 Pro Max are three months away, and there are plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of June 2025:Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone X through iPhone 14 Pro have a...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro's Alleged Vapor Chamber Cooling System Partly Revealed

Sunday June 22, 2025 6:37 am PDT by
Apple's upcoming iPhone 17 Pro and iPhone 17 Pro Max models are rumored to be equipped with a vapor chamber cooling system, and a leaker known as Majin Bu today shared a photo of an alleged copper thermal plate for the system. Many high-end Android smartphones like Samsung's Galaxy S25 Ultra are equipped with a vapor chamber cooling system, which can manage heat dissipation inside the...
Wi Fi WiFi General Feature

iOS 26 Adding Two New Wi-Fi Features, Allows AirDrop and AirPlay Alternatives

Saturday June 21, 2025 7:02 am PDT by
iOS 26 is gaining two new Wi-Fi features, including Captive Assist and Wi-Fi Aware. MacRumors contributor Aaron Perris discovered a reference to Captive Assist within the code for the first iOS 26 developer beta, but Apple has yet to enable the feature. It should be available by the time the software update is released later this year. In his Power On newsletter last month, Bloomberg's...
apple watch ultra 2 new black

Apple Watch Ultra 3 Finally Coming After Two-Year Hiatus

Monday June 16, 2025 8:45 am PDT by
Apple will finally deliver the Apple Watch Ultra 3 sometime this year, according to analyst Jeff Pu of GF Securities Hong Kong (via @jukanlosreve). The analyst expects both the Apple Watch Series 11 and Apple Watch Ultra 3 to arrive this year (likely alongside the new iPhone 17 lineup, if previous launches are anything to go by), according to his latest product roadmap shared with...

Top Rated Comments

everlast3434 Avatar
36 months ago
Can’t wait to try this out while sitting in the couch, flipping through the channels, and drinking a beer! Lol
Score: 21 Votes (Like | Disagree)
MayaUser Avatar
36 months ago
nice battery but 3years old SoC on it...sry but they should place a new SoC at least in this Ultra
Score: 18 Votes (Like | Disagree)
DMG35 Avatar
36 months ago
I’m really excited to get this in and try it. Its big and exactly what I was hoping for.
Score: 17 Votes (Like | Disagree)
pauloregan Avatar
36 months ago
Does SOC mean 'same old crap'?
Score: 17 Votes (Like | Disagree)
MacWorld78 Avatar
36 months ago
"Apple Watch Series 8‌ featuring the same CPU as the Series 6 and 7" :rolleyes:
Score: 14 Votes (Like | Disagree)
boak Avatar
36 months ago

nice battery but 3years old SoC on it...sry but they should place a new SoC at least in this Ultra
That's how they are going to sell the next Ultra ;)
Score: 11 Votes (Like | Disagree)