Huawei Watch D2 review

The Huawei Watch D2 is the company's second watch to come with blood pressure monitoring. Imagine a smartwatch that not only tracks your steps and heart rate but also brings advanced blood pressure monitoring right to your wrist with the ease of a built-in inflatable cuff.

Like all other Huawei smartwatches, the Watch D2 works with Android phones and iPhones. It has all the modern features you may expect - heart rate and SpO₂ tracking, sleep tracking, skin temperature, ECG, sleep breathing and arterial stiffness assessment, as well as tracking various types of exercise on demand. It will also help you stay on top of your phone's app notifications, and you can even take calls on it while it's connected to your phone via Bluetooth.

Hardly any of this is groundbreaking functionality- the Watch D2 does not differ much from the other Huawei smartwatches we've reviewed recently, like the Watch GT 5 or the Watch GT 5 Pro. So, in this review, we won't be getting into details about every feature that has been covered before. Instead, we'll focus on battery life testing and checking how accurate blood pressure tracking is.

Table of Contents:

• Design
• Display
• Battery Life
• Charging
• Blood Pressure Measurement
• Verdict

Design and build quality

The watch has a familiar design and layout (to the point of looking generic), but it's undoubtedly a looker. The white composite leather strap and the subtly golden body on our review unit look exceptionally stylish.

In the box, you get a magnetic charging puck with a built-in USB-A cable (no charger) and straps in two sizes.

The strap itself feels incredibly comfortable to wear and easy to adjust in length on the go, should you need that.

The watch is also very light, and wearing it 24 hours a day felt seamless and comfortable.

The body is made of aluminum. It turned out that the screen glass and the shiny bezel around it were easy to scratch. Huawei's Pro series watches seem much more durable in this respect.

The watch body is IP68-rated, but Huawei advises against having it on your wrist while taking a hot shower, swimming, or diving, which is a bummer. Other smartwatches (Huawei's included) are fine to take with you while swimming.

The watch has a 1.82-inch OLED screen and a pixel density of 347ppi. Legibility is excellent in direct sunlight (possibly due to the promised 1500-nit peak brightness), and automatic brightness control works great.

The body measures 48 x 38mm and is slightly thicker than your usual smartwatch in this format. After all, it has a miniature air pump inside to inflate the cuff in the wrist strap.

Removing the wrist straps for cleaning is easy and requires no tools. As you might imagine, the straps are not standard, so you can't use a third-party one.

Removing the strap is easy and doesn't require any tools

Software

The watch is based on HarmonyOS 5.0, Huawei's latest wearable OS. From what we could tell, no features are missing compared to the company's other watches.

With v5.0, you get nudging prompts throughout the day to reach your daily activity goals. You also get access to sleep breathing assessment at night, and you now have some new first-party apps like a Calculator.

Like before, you can download a few third-party apps as well, but their usefulness will depend on your use cases. They usually require a host app installed on your phone; and some (like Petal Maps) would not work with an iPhone.

HarmonyOS 5.0 also comes with an on-screen QWERTY keyboard if you need to type a reply to a message in a pinch. You also get the option to take a screenshot of the watch screen.

Overall, HarmonyOS seems well optimized in fluidity and battery life, but we feel it still has limitations. Auto exercise detection is unreliable, and recognizing that you've started exercising is often very late compared to other watches. The automatic prompt every morning to measure your blood pressure is not very smart, coming up according to schedule every day, even if you've just finished measuring before that. Some features, such as Wallet or Mental health assessment, are regionally limited.

On the positive side, getting a GPS lock for outdoor activity tracking is very fast. The software is very fluid, and notifications work very well (even though the icons don't match the icons of the real app).

You control the interface by rotating and pressing the crown or selecting apps and icons directly on the screen.

Battery life

There is a 524 mAh battery inside the Huawei Watch D2, and battery life was stellar in a month or two we used it daily.

With Always-On Display (AOD), you get 6 days' worth of operation on a single charge as the watch loses about 15% charge per 24h. Adding 5-6 blood pressure measurements per day did not take any extra toll on the battery life.

The Watch D2 really shined with AOD off, as, in this setup, it easily lasted 10 days on a single charge, losing 10% of charge per day.

We confirmed both battery life measurements across several charging cycles, and for all of them, we had turned on all onboard health and step-tracking features (but we didn't have any exercise-tracking sessions).

Charging speed

We tested the charging speed by pairing the bundled magnetic charging puck with a 40W Huawei charger, which we had lying around.

A full charge took 98min, which is somewhat slow. The watch's charge level showed 37% at the 30-minute mark, 67% at the 60-minute mark, and 94% at the 90-minute mark.

Blood pressure measurement

Smartwatch manufacturers have had blood pressure measurements in their sights for a while now, and a few of them are already offering the feature with varying degrees of user-friendliness.

Blood pressure measurements on other smartwatches require regular calibration with a proper blood pressure monitor and, in our experience, rarely work very seamlessly, often requiring retesting and retrying, which is not very user-friendly.

Compared to those watches, the inflatable cuff system used in the Watch D2 and its predecessor - the Watch D - provides great usability and ease of use. However, blood pressure measurements here are not without their caveats - the biggest being accuracy consistency.

The caveats about accuracy are not specific to the Huawei Watch D2. Wrist cuff monitors (Even the one from the pharmacy) are inherently less consistently accurate than their arm cuff counterparts.

With a wrist cuff monitor, you always have to take three readings and average them out to ensure you get a reading that can be considered accurate. These average numbers can still be +/- 5 points off compared to a good arm cuff monitor, but that's fine.

You must use good form and ensure consistent conditions (body pose, clothing, even ambient temperature) to get consistent measurements from any wrist cuff monitor. Through trial and error, we discovered that the pose that Huawei suggests you assume for blood pressure measurement should be considered an absolute requirement and not a mere recommendation.

The correct form during measurement is paramount for the accuracy consistency

For this review, we used 3 dedicated blood pressure monitors to gauge how accurate the Watch D2 really is. We had a Panasonic wrist cuff monitor and two Omron arm cuff monitors - a modern Bluetooth-connected one that's built into the cuff itself as well as a regular two-part monitor, which uses a cuff just like the one that can be found in your doctor's office. And the results were quite intriguing.

The regular two-part electronic blood pressure monitor was the most accurate of the bunch, producing reliable and consistent results time after time, regardless of whether you were measuring blood pressure while sitting or lying down (we acknowledge that the two poses produce different results and we never compared the two directly).

The Bluetooth-enabled single-piece Omron monitor was a close second in consistency. There were still slight variations from measurement to measurement, which required three measurements to be taken each time to average the result. Still, the averaged results you'd get with this monitor were quite reliable and close to the ones with the first monitor (often identical and within 2-3 points of difference at worst). Measuring BP both when sitting and lying down was fine.

The two wrist cuff monitors - the Watch D2 and the Panasonic one - were the least consistently accurate. We discovered that using any of these two necessitated 3 consecutive measurements every time, but even that was not enough. Both monitors could produce accurate measurements, but this relied heavily on using the proper body position during measurements.

When the proper form was adhered to, the average results from the wrist monitors were spot on, usually deviating only up to +/-3 points from our reference BP monitor.

Sometimes, even with our best efforts to maintain consistent measurement parameters and form, there were still occasions where we got as much as +/- 7-8 points off.

That accuracy is still quite reasonable for a blood pressure monitor that can always be on your wrist, and measuring your blood pressure regularly and often can easily help clean up these outliers over longer periods of data recording.

However, if you plan on using wrist cuff monitors to only occasionally check your blood pressure, you may be disappointed by the consistency of the measurement accuracy.

Also, the two wrist cuff monitors produced unreliable results when measuring blood pressure lying down so we can't recommend them for this use case.

Huawei has also built into the Watch D2 the option to perform 24-hour Ambulatory Blood Pressure Monitoring on request by the user. You start the program manually, and the watch can either perform the measurements automatically throughout the day or nudge you to start them manually when it's time.

However, we wouldn't trust the results from a 24-hour Ambulatory Blood Pressure Monitoring with a wrist cuff monitor due to the inherent consistency issues if you don't ensure consistent sitting body pose for every measurement.

Overall, we were happy with the overall accuracy of the blood pressure measurements provided by the Watch D2. As long as you perform at least three consecutive measurements and average them every time, and you always ensure consistent measuring conditions and proper form, it should serve quite well someone who not only appreciates the smartwatch functionality but would also want to keep track of their blood pressure regularly.

Verdict

The Watch D2 costs £350/€400, more than the current flagship Huawei Watch GT 5 Pro. The built-in inflatable cuff for blood pressure monitoring makes this a unique proposition.

Compared to the Watch D, the new model has a more upmarket design, more compact body, longer battery life and a newer HarmonyOS. There is also the improved motion tracking, the barometer and the ECG functionality. We didn't have the two side by side to compare the accuracy or consistency of the measurements, so we can't comment on that. The Watch D will also be harder to find in stores, as it's already being phased out.

The Huawei Watch D2 is hard to beat for a blood pressure monitoring smartwatch. The engineering that has gone into creating it is commendable. However, this convenience comes at a price.

If you are not interested as much in blood pressure monitoring and you merely want a smartwatch with long battery life, you can get 90% of the features available here with the Huawei Watch Fit 3, which costs less than half the money. This retail price difference means you are essentially paying upwards of €200 for a blood pressure monitor with finicky accuracy and consistency. This much money can get you a high-end compact, connected one-piece arm cuff monitor that will help you stay on top of your blood pressure faster, more consistently and with less attention to proper form.

However, in the end, the best blood pressure monitor is the one you actually use daily. So, if having something like the Watch D2 always on your wrist will finally get you to check your blood pressure more regularly, then the price is definitely worth it.

Pros

• Upmarket look and feel.
• Display is sharp and performs great in any environment.
• Inflatable strap is incorporated seamlessly and inconspicuously.
• Intuitive user interface with fluid performance.
• Great battery life.
• Fast and solid GPS lock during exercise tracking.
• Accurate blood pressure measurement (with a few caveats).

Cons

• The metal and glass scuff more easily than other Huawei watches.
• Not suitable for swimming or showering despite IP68 rating.
• HarmonyOS 5 still has some odd limitations, and apps are limited.
• Accurate blood pressure measurement requires proper form and conditions (valid for any wrist cuff monitor).
• Individual blood pressure measurements are often off (valid for any wrist cuff monitor), and the watch does not automatically average consecutive measurements.