OnePlus Watch 3 Review: The Smartwatch with the Best Battery Life in 2025

Battery life is often the deal-breaker when it comes to smartwatches. Nobody wants to charge their wearable every single night—or worse, discover it dead right before a workout or a day out. Yet despite years of progress, major players like Apple, Samsung, and Google still can’t seem to break past the 2-day mark without sacrificing features. That’s where the OnePlus Watch 3 comes in.

With a massive battery, refined hardware, and slick Wear OS performance, the OnePlus Watch 3 isn't just bigger—it’s smarter, faster, and, most impressively, longer-lasting than any other Android smartwatch in 2025.

OnePlus Watch 3 specs

Materials	Size & weight	Battery life	Display	Operating system	Connectivity
Titanium bezel, stainless steel case, sapphire crystal glass	47.6mm*11.75mm, 81g	5 days with general use	LTPO AMOLED, Up to 2200 nits Peak brightness	Wear OS by Google + RTOS	Dual band L1+L5, Beidou, GPS, Galileo, GLONASS,QZSS WiFi 5G/2.4G Bluetooth 5.2 Support NFC Bluetooth calling

 

Design & display: Bigger, better?

My first impression after unboxing is that the OnePlus Watch 3 is big. Measuring at 46.6mm and weighing 81g (strap included), it’s a hefty piece of wrist candy. That might be a turn-off for users with smaller wrists, but the improved strap design helps offset the size, offering a snug and comfortable fit that keeps sensors accurate.

Of course, a bigger watch means a better display. The 1.5-inch LTPO AMOLED display is indeed easy on the eyes. With 2,000 nits of peak brightness and 2D sapphire crystal protection, the screen is both vibrant and durable, rivalling more premium options like the Apple Watch Ultra 2. The rotating crown and customizable side buttons make navigating through menus effortless. I also loved the circular design, which is closer to the aesthetic appeal of a luxury timepiece, in contrast to OnePlus’s squarer rivals. 

Performance & features: Dual-chip that packs a punch

With dual-chip architecture (Snapdragon W5 and BES2800), it's no surprise that the OnePlus Watch 3 delivers a noticeably smooth performance. Everyday tasks, like taking calls, checking notifications, responding to messages, and navigating via GPS, feel fluid and responsive. And with 2GB of RAM and 32GB of storage, there’s plenty of room for apps. 

That said, the UI can feel unintuitive at times. Features like workout customization and battery saver settings are tucked away, and the OHealth app, while feature-rich, can take time to configure. Still, the customizable rotating crown shines here, especially when paired with the app grid zoom feature.

It’s worth pointing out that OnePlus promises software support until 2027, which is shorter than rivals like Samsung. But for anyone focused on performance now rather than long-term updates, it’s a worthy trade-off.

 

Health & fitness tracking: Across-the-board accuracy

OnePlus has seriously levelled up its health features this year. The Watch 3 includes an 8-channel heart rate sensor, a 16-channel SpO2 sensor, wrist temperature tracking, ECG (outside the U.S. and Canada), and even arterial stiffness analysis. From real-time heart rate monitoring to future-ready features like sleep apnea detection, the sensor suite is extensive and generally reliable.

The 60-second Health Check-In is a standout, offering quick snapshots of six vital metrics. Plus, the revamped OHealth app delivers granular sleep and wellness data. While some features like stress tracking feel vague, the watch nails the essentials.

One caveat: the watch’s bulk may make sleep tracking a bit uncomfortable for some users.

Battery life & charging: The best in the business  

If battery life is what you're after, the OnePlus Watch 3 is hands-down the best Android smartwatch of 2025. With its 631mAh silicon-carbon battery and power-efficient dual-chip design, it lasts up to five days in Smart Mode with full features enabled, or an impressive 16 days in Power Saver Mode.

In real-world testing, I consistently reached the five-day mark with sleep tracking, GPS workouts, and health monitoring turned on. Even with a non-optimized, battery-draining watch face, it still delivered four days of use—far outpacing competitors like the Pixel Watch 3 or Galaxy Watch 7.

But what truly sets the OnePlus Watch 3 apart isn’t just how long it lasts; it's how quickly it recharges. You’ll get to 80% in just 30 minutes and 100% in under an hour via USB-C fast charging. For anyone tired of nightly charging rituals, the Watch 3 is a revelation.

HeyUp's verdict: OnePlus delivers where it matters most 

The OnePlus Watch 3 is a bold step into flagship smartwatch territory, and it mostly sticks the landing. With its standout five-day battery life, premium build, dual-chip architecture, and sharp performance, you've got a compelling mix of endurance and smarts that few competitors can match. While its larger size may not suit everyone, this trade-off feel minor in the face of its overall power. If battery life is your top priority, the OnePlus Watch 3 is easily the best pick for you. 

Pros

• The best battery life of any Android smartwatch

• Accurate and wide-ranging health tracking

• Reliable performance

• Customizable rotating crown

Cons

• Size might be too big for small wrists

• Somewhat cumberstone UI

• Shorter software support window (until 2027)

Perfect for:

• Anyone looking for a smartwatch with unbeatable battery life and awesome health tracking.

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