Apple Watch Series 11 review: I tracked my health for a week, and the battery life blew me away

Apple Watch Series 11 ZDNET's key takeaways Apple's baseline smartwatch offers upgraded health features and additional battery life. The smartwatch's only weakness is that it's trumped by the value of its younger sibling, the SE 3. The Series 11 is available to preorder now and ships on Sept 19. View now at Apple Follow ZDNET: Add us as a preferred source on Google. People wear Apple Watches for all sorts of reasons. There are the health and sleep tracking functions, which Apple has heavily invested in over the past few years. There's the second-screen aspect - some jobs prohibit workers from using their phones on the clock. And then there are the phone-free perks of disconnecting, albeit with some safeguards for contacting friends, listening to music, or getting directions. Apple rolled out three new Apple Watches at its September iPhone event this year (the Apple Watch Series 11, Apple Watch Ultra 3, and the Apple Watch SE 3), and I have been testing all three for the past week. Now I'm ready to share pros, cons, use cases, and buying advice for each one. Also: AirPods review: Apple pulled off something I thought was impossible In this review, I'm going to focus on the Apple Watch Series 11, which I used to track workouts at my Brooklyn gym, monitor my sleep, and receive Apple's brand-new Sleep Scores, and do a whole lot more. So, is this a smartwatch to buy or upgrade to? Let's get into it. Some features stay the same from Series 10 to Series 11. The biggest is Apple's chipset. Normally, it updates its chips every year, but the Series 11 keeps the S10 processor, the same chip as 2024's Series 10. Apple says that in adding more battery life through an internal design change that replaced its jelly roll cells with a metal can design, it was able to keep the form factor of the watch the same and use 2024's chip to process the new device. This means that the build of the watch is identical to the Series 10. The screen brightness also remains the same at 2,000 nits, despite its competition, the Pixel Watch 4 and Galaxy Watch 8, amping theirs up to 3,000 nits. You have to upgrade to the Apple Watch Ultra 3 to get a 3,000 nit screen in the Apple ecosystem. Also: The ten features that made me switch to the Apple Watch full-time The new watches come in four colorways: Jet Black, Rose Gold, Silver, and a new Space Gray. My band of choice is the Sport Loop, which I tested in a striking Neon Yellow. I wasn't expecting to love as much as I did: It's lightweight on the wrist, easy to sleep with, and water-wicking (especially if you shower with your watch, which I do). Apple also improved the Sport Loop band for added reflectivity around the edges for those nighttime runners and outdoor exercisers. Nina Raemont/ZDNET Sleeping, working, and exercising with the watch is a lightweight and comfortable experience. The display is vivid, notifications pop up quickly, and the watch outlasts a day of regular use. If you haven't slept with a watch before, it might take a few nights to get used to it. But the thin build of the Series 11 and the sleep mode, which blackens the screen and dismisses interruptions, make it easier than other watches to drift away. The upgrades you should know about Apple made several upgrades to the Series 11 that its predecessor, the Series 10, misses out on. The most desired update is six additional hours of battery life. The battery boost brings the overall capacity to 24 hours for all-day communication, activity tracking, and sleep tracking. The FDA-cleared Hypertension Detection feature is another big one, not just for those who want to further understand their blood pressure without needing a blood-pressure cuff but also for Apple's long-term mission to use technology to proactively improve health and wellness. Also: Avoid buying these 4 Apple products this week The new hypertension feature doesn't provide by-the-minute readings on blood pressure. Instead, it uses Apple's PPG heart sensor to take a 30-day average reading that its algorithm determines is either above or below the hypertension threshold. Because I had only a few days with the watch, I wasn't able to use the feature yet as it requires 30 days of monitoring, but I'll report back in a month once I have further experience with it. Still, hypertension impacts over 1 billion people and is the world's most undiagnosed disease. Apple's first-of-its-kind, FDA-cleared hypertension detection will not only encourage proactive monitoring but also spread awareness of the condition's ubiquity. Apple forecasts that its new hypertension feature will notify over a million people of their undiagnosed high blood pressure during its first 12 months on the market. Nina Raemont/ZDNET Apple adds 5G to Series 11 for efficient connectivity, Ion-X glass for durability, and a wrist-flicking gesture to dismiss messages or calls. The new glass could help close the durability gap between the Series 11 and Ultra 3 and make the cheaper smartwatch even more appealing to those stuck between the two. Interestingly enough, this year, several upgrades are not exclusive to the three new Apple Watches' new hardware. The software upgrades in WatchOS 26 extend beyond the Series 11, Ultra 3, and SE 3 to the Series 9 and later and Ultra 2. What I'd like to see on the Series 12 I found that Apple's new Sleep Score tended to inflate my quality of sleep. I tested the watch against my Oura Ring, which delivers sleep and readiness scores every morning. My Apple Watch regularly delivered scores in the high 90s when my Oura Ring offered up scores in the 80s, even on days when I felt sluggish and needed a nap. Apple says it bases the three factors that make up your Sleep Score on guidelines from three leading sleep foundations. Also: The Apple Watch Series 11 is one feature away from making me ditch my Oura Ring In general, sleep scores are a fairly subjective metric that tech brands generate to visualize sleep health easily. Throughout my testing of sleep trackers, I've found that a sleep score reflects the brand's priorities more than it is an objective measure of sleep tracking. If most Americans aren't getting good sleep, according to recent stats, and Apple is appealing to a general American consumership, its sleep score metrics might be generous to assuage the user. Any consistent, seven-hour slumber with few interruptions could still land you an 80 or 90-something sleep score. Nina Raemont/ZDNET Despite their subjectivity, sleep scores convey sleep information in an easily digestible way, much to the dismay of poor sleepers. Many people have stopped using sleep trackers because of sleep scores that grade them poorly. It's in a brand's best interest to make products that don't alienate the user while also delivering useful, accurate information. Apple says it is doing so by only grading a user on their bedtime consistency, interruptions, and sleep duration. Additionally, Apple is already capturing a wearer's Training Load, and I'd love to see Apple add some sort of Recovery score that takes a user's activity data into account and optimizes their Training Load metric each day. ZDNET's buying advice When comparing the Apple Watch Series 11 to the Ultra 3 or SE 3, there are a few qualities that distinguish the watches. Every smartwatch, for example, now includes the Sleep Score, but the SE 3 gets 18 hours of normal use battery life, while the Series 11 gets 24, and the Ultra 3 gets 42. The Ultra 3, like the Series 11, includes Hypertension Detection while also adding Emergency SOS via Satellite. Emergency SOS and 42 hours of battery life would serve hikers and people who work in rugged professions. First-time smartwatch users looking to record a workout or discreetly respond to texts on the job would probably get the most out of Apple's affordable SE 3. So, where does that leave the Apple Watch Series 11? Also: I compared Apple and Samsung's best smartwatches - here's who wins for now The Series 11 is ideal for you if you have already used a smartwatch regularly and are ready for an upgrade. You might be using it for exercise and for closing your daily activity rings, and you want to further understand your health through Apple's Sleep Score, Hypertension Detection, the Vitals app, and advanced exercise features like Training Load. You have used a previous smartwatch regularly enough to know you need more battery out of your next one, which makes the Series 11's 24-hour capacity a key upgrade. WatchOS 26 brings Sleep Score and Hypertension Detection to earlier watches, including the Series 9 and later, and the Ultra 2. It skips the SE and SE 2. So the bigger question is whether Series 11 shoppers should consider the Series 10 instead? If you don't need the extra six hours of battery life and want to maximize your savings, then the Series 10 is still a great choice. You can even find a refurbished one for under $300 on Amazon and other retailers. Keep in mind that whichever Apple Watch you choose, there are usually excellent discounts around Black Friday, and ZDNET will always keep you updated on the best deals. For more on those two products, take a look at my reviews of the Apple Watch Ultra 3 and Apple Watch SE 3.