Xiaomi 15: compact flagship with high battery life

The new Xiaomi 15 smartphone, at first glance, is quite difficult to distinguish from its predecessor Xiaomi 14. The models have almost identical design, display, and cameras. Therefore, it may seem that this is a rather minor update. However, Xiaomi actually took a thorough approach to creating a new version of its mass flagship. Whether these innovations have become useful and what the Xiaomi 15 can offer, I will tell you in detail in the review.

The editorial team would like to thank the Allo company for kindly providing the Xiaomi 15 smartphone for review.

Specifications of Xiaomi 15

Package contents

Despite the fact that the Xiaomi 15 comes in a box of the same size as its predecessor, the Xiaomi 14, its package has been somewhat slimmed down. Along with the smartphone, users will still be able to find the branded silicone case, USB-C cable, and documentation, but the power supply is no longer included. It's a bit of a shame, because previously the company included a branded 90W fast charger in the box, but now you will have to buy it separately.

Design and ergonomics

The changes in the design of the Xiaomi 15 are not very significant, in the spirit of the new flagships, the smartphone received smaller display frames - 1.38 mm, thanks to which its dimensions also became slightly smaller: 152.3 x 71.2 x 8.08 mm versus 152.8 x 71.5 x 8.2 mm in its predecessor, the Xiaomi 14. The front panel is also occupied by a 6.36-inch screen with a small cutout for the selfie camera at the top, but now it is covered by the Xiaomi Shield protective glass. The company provides very little information about this glass, only indicating that it shows 10 times better durability than the Gorilla Glass Victus in the Xiaomi 14. That it does not matter. In any case, the glass breaks and can be scratched and it is worth thinking about additional protection, although it is worth noting that the Xiaomi 15 immediately comes with a protective film on the display.

The smartphone has a flat metal frame that slightly protrudes from the back of the case. This is another small change in design, as in the previous generation it was the opposite, the rear glass panel was rounded at the edges.

The camera module hasn't changed much either: it has the same shape and size, except that the flash that mimicked the fourth camera has been removed. In its place are barely noticeable sensors, including laser autofocus, and the flash itself is now located to the right of the camera module.

The back of the Xiaomi 15 is made of matte glass, which does not leave fingerprints. In this regard, the smartphone is generally well thought out, even if you wear it without a case, the matte surfaces will not get dirty. However, it is worth noting that the rounded edges and matte surface of the frame make the device quite slippery, you need to get used to it. This is also affected by the weight of the case, which, despite the more compact dimensions and smaller thickness, has grown to 191 grams.

The Xiaomi 15 case also has IP68 protection, the smartphone can be used in the rain and it must withstand immersion to a depth of 1.5 meters for up to 30 minutes.

Overall, we have cosmetic changes in the design, but they not only refresh the appearance of the model, like smaller bezels around the screen, but also add usability, like more compact dimensions and thickness.

Display

The Xiaomi 15 features a 6.36-inch CrystalRes AMOLED matrix with a resolution of 2670x1200 pixels (460 ppi), a refresh rate of 1 to 120 Hz, support for the DCI-P3 color space, as well as Pro HDR, HDR10, HDR10+ and Dolby Vision. Compared to the screen in last year's Xiaomi 14, the only notable innovation is the increased peak brightness to 3200 nits.

The Xiaomi 15 supports reducing display flicker at low brightness levels through DC Dimming backlight control, but there is no longer a corresponding option in the display settings. Flicker reduction is now enabled automatically.

Like most smartphone manufacturers, Xiaomi is trying to add more AI features to its models, including display settings. There’s a whole section called “AI Visualization System” where you can enable features like AI-powered video upscaling, HDR enhancement, and frame redrawing to improve video smoothness. In fact, the Xiaomi 15 offers a suite of technologies to enhance video playback, similar to modern AI-powered TVs. Each of these features comes with a disclaimer that they slightly increase battery drain. So you have to weigh whether you’re after a better video or a longer battery life.

Otherwise, the smartphone has display settings typical of modern flagships, you can choose a dark or light theme with automatic switching depending on the time of day, change the color scheme, activate reading mode to reduce the amount of blue light, and also switch from automatic detection of the refresh rate to 60 or 120 Hz.

Security

The Xiaomi 15 has several options for unlocking the screen. In particular, it is less reliable due to facial recognition, which works thanks to the built-in camera. But there is also a fingerprint scanner. Last year's Xiaomi 14 used an optical fingerprint sensor, which worked quite accurately. But the new product has a newer ultrasonic fingerprint scanner, which has several advantages. Firstly, it does not light up when triggered, which is less eye-catching when unlocking a smartphone in the dark, and secondly, the ultrasonic sensor is less sensitive to water or dirt on your fingers, which means it works more reliably.

Productivity and software

The Xiaomi 15 is powered by the flagship Qualcomm Snapdragon 8 Elite processor with Adreno 830 graphics, which is complemented by 12 GB of LPDDR5X RAM and 256 or 512 GB of fast UFS 4.0 storage. Interestingly, the operating system allows you to increase the “RAM” by another 4, 6, 8 or 12 GB using the built-in storage. By default, the system allocates an additional 4 GB for RAM.

As expected, the speed of the Xiaomi 15 is at a very high level, the smartphone has a good performance margin, which will definitely be enough for several years to come. This is confirmed by synthetic tests, in which the device demonstrates high performance.

The same goes for games, it's comfortable to play both Minecraft or BrawlStars on a smartphone, as well as more demanding games like Northgard or WoT Blitz.

The previous generation of the model heated up quite noticeably during high load, but it is worth noting that only in tests that create a higher load than modern applications or games on Android can. The situation is similar with Xiaomi 15, in the 3DMark Wild Life Extreme stress test the smartphone demonstrates stability at 72%, which is significantly higher than the typical 48-55% in modern flagships. After all, during an increase in load and case temperature, they reset the processor frequencies, thereby reducing performance. Xiaomi decided to take a different approach, even despite the increase in case temperature to 51 degrees Celsius, which is already quite noticeable, if you hold the smartphone in your hands without a case, the processor frequencies do not decrease, it stably keeps performance at the highest level, which is clearly visible in the 3DMark graph.

Considering that real-world applications and games are not yet capable of creating a similar level of load, Xiaomi's approach has the right to life. At least, during everyday use, the device does not heat up much and is comfortable to use.

Other features of the Xiaomi 15 platform include support for Wi-Fi7 wireless modules, Bluetooth 6.0 with codecs for wireless audio transmission SBC/AAC/AptX/AptX HD/AptX Adaptive/LDAC/LHDC 5.0/LC3, as well as NFC. For navigation, there is support for GPS, GLONASS, GALILEO, BDS, QZSS and NavIC satellite systems.

The smartphone supports two physical nano-SIM cards, and you can also connect mobile communication and the Internet via eSIM.

Another interesting feature of the Xiaomi 15 is the infrared transmitter located in the camera unit, which allows you to use your smartphone as a remote control. There is a separate application from Xiaomi for this.

In addition, the device allows you to measure your pulse. But if in its predecessor Xiaomi 14 this function worked through an optical fingerprint scanner, and since the scanner in Xiaomi 15 is now ultrasonic, now the pulse is offered to be measured by activating the flash and placing a finger on one of the cameras. It is quite inconvenient, but it works.

Xiaomi 15 comes with Android 15 operating system and its own proprietary HyperOS 2.0 interface. Overall, it is a convenient shell with fast operation, smooth animations and extensive customization options to suit your needs.

However, it also inherited the shortcomings of the previous version, including advertisements in some system applications and applications like "Mi Browser" or the GetApps app store, which cannot be disabled or uninstalled. Another rather strange solution is a separate application for scanning QR codes, because usually this function is automatically triggered by the smartphone's camera.

Otherwise, HyperOS 2.0 leaves a pleasant impression after use.

Cameras

The set of cameras in the Xiaomi 15 has not changed, the smartphone still uses three main modules with LEICA VARIO-SUMMILUX 1:1.62-2.2/14-60 ASPH lenses:

• The 50-megapixel OmniVision OVX9000 sensor is Xiaomi's own development, which the company calls Light Fusion 900. It has a physical size of 1/1.31" and provides a dynamic range of 13.5 EV. The optical system is represented by an aperture of f/1.6 and an equivalent of 23 mm. The equipment includes phase autofocus based on dual pixel PDAF, laser autofocus and optical stabilization. In standard mode, the camera uses pixel binning to create images with a resolution of 12.5 MP, but a 50 MP shooting mode is also available.

• 50-megapixel telephoto camera with a 1/2.76" Samsung ISOCELL JN1 sensor and 0.64 μm pixel size. The lens has an f/2.0 aperture with a 75 mm focal length, is equipped with a movable lens group, which allows you to focus on objects located from 10 meters to infinity. In addition, this camera supports 2.6x optical zoom and is equipped with optical stabilization.

• The 50-megapixel ultra-wide-angle camera uses the same Samsung ISOCELL JN1 sensor, has optics with a focal length of 14 mm, providing a 115˚ viewing angle, and is not equipped with autofocus.

The front camera is equipped with a 32-megapixel OmniVision OV32B sensor, with an f/2.0 aperture and a 1/3.14" sensor size.

As for video, the maximum resolution is 8K at 24 FPS, and there is the possibility of recording with extended dynamic range.

The main camera shows excellent image quality in most conditions. Photos taken during the day are detailed with rich and natural colors. Night mode also works well, although sometimes the effects of processing are noticeable.

The telephoto camera shows a high level of quality during the day, providing clear and detailed shots in most situations, but the smaller aperture leads to a decrease in detail at night.

The ultra-wide camera has limited dynamic range, but overall it takes good photos during the day. However, at night, the quality of the images drops due to the relatively small aperture and lack of optical stabilization.

In general, although the camera capabilities remained at the level of last year's Xiaomi 14, they provide good image quality in most conditions.

Sound

The smartphone has two speakers, one combined with the speaker, and the second is located on the bottom edge of the case, which allows you to create a noticeable stereo effect. The Xiaomi 15 sounds loud and voluminous, there are even hints of bass. Considering that this is a relatively compact smartphone, the sound of the speakers can be called very good.

Battery life

Another big innovation in the Xiaomi 15 is the battery. It has grown from 4610 mAh in the predecessor Xiaomi 14 to 5240 mAh, and this is with a smaller body thickness. This change was made possible by the use of a new type of battery – silicon-carbon lithium-ion (Si/C Li-Ion), which allows for increased capacity with smaller battery sizes. Of course, this had a positive effect on the autonomy of the Xiaomi 15, in the PCMark Work 3.0 test the smartphone lasted 19 hours and 6 minutes at a screen brightness of 200 nits, which is a very good result.

In real use, the device also demonstrates very good autonomy; if you charge it at 7 am, 48-55% of the battery charge remains by 12 midnight. In fact, we can talk about almost two full days of work on a single charge.

The smartphone supports fast wired charging up to 90W, wireless charging up to 50W, and reverse charging up to 10W.

The editorial team would like to thank the Allo company for kindly providing the Xiaomi 15 smartphone for review.