Ulefone Armor Mini 20T Pro in test

A small smartphone plays a big role: The Ulefone Armor Mini 20T Pro is an outdoor cell phone with 5G and a thermal imaging camera. Testing shows what it can do.

The Ulefone Armor Mini 20T Pro with a 4.7-inch display impresses with its combination of compact design and strong outdoor suitability. It’s one of the smallest outdoor smartphones on the market, but it still offers solid performance along with a powerful battery, 5G support, and a FLIR thermal imaging camera. But how does the little giant perform in everyday life? That’s what our testing of China’s rugged phones shows.

Ulefone Armor Mini 20T Pro is one of the most compact smartphones currently. Along with the Blackview N6000 (test report), this is the smallest outdoor cell phone we’ve tested so far. The design follows the martial principles of a typical outdoor smartphone: angular housing, with rubber coating on the corners and back and metal elements on the sides. The front camera is housed in a punch-hole notch in the middle – which is not offered on outdoor cell phones.

At 133.5 × 63.3 × 24.9 mm, it’s almost as big as the iPhone 13 mini (test report) – but more than three times as thick. To accommodate the powerful battery, it was necessary to make the device two fingers thicker. Exclusive to Ulefone: on the right side there is a power button with a fingerprint reader and on the left side there are two round buttons for volume, with an orange, programmable button. There’s a 3.5mm jack connection at the top and a slot for USB-C at the bottom. Both openings are secured with rubber tabs. Anything except the Mini weighs around 300 grams – twice as much as the iPhone 13 Mini. But it is easier for outdoor smartphones.

Small cell phone can withstand big punishment: In testing, the device survived a fall on hard asphalt without any scratches. According to the manufacturer, this applies to a fall height of up to 2 meters. For this purpose, the Armor Mini 20T Pro is certified for drops according to the US military standard MIL-STD-810H. The display is protected by Gorilla Glass Victus. It is also dust and waterproof according to IP69K. According to Ulefone, it can survive underwater for 24 hours at a depth of 2 meters. It should also operate reliably in a temperature range of -20 to 55 degrees Celsius.

The smaller display measures 4.7 inches diagonally – a bit of nostalgia there. Because the days of such small smartphones seem to be over. Its nominal HD resolution is only 1600 × 720 pixels. Despite its size, it still offers a very high pixel density of 373 ppi, where pixels can no longer be seen by eye. Speaking of eyes: if you suffer from presbyopia, like the author of this test, the Ulefone Armor Mini 20T Pro will make a lot of demands on you. To read the display well, you will need reading glasses.

The IPS panel offers moderate high viewing angle stability. Image quality is reliable. Thanks to the refresh rate of up to 90Hz, animations or scrolling activities appear smooth. We were able to measure a maximum brightness of around 515 nits. This is only a modest bright value, even though the manufacturer talks about up to 700 for automatic brightness adjustment. But it’s still better than many other outdoor cell phones. The display can usually be read outdoors; It is advisable to find a shady spot only in bright sunlight.

The camera equipment is impressive. Apart from a 50-megapixel (f/1.95) main camera and a 32-megapixel (f/2.45) selfie lens, the Armor Mini 20T Pro offers a thermal imaging camera from Flir.

By default, the camera combines four pixels into one, creating 12.5 megapixel images. More details can be obtained from this. If you want, you can even go up to the full 50 megapixels. During the day, the lens delivers sharp images with attractive image detail, even if colors appear a little subdued. With 2x digital zoom, photos appear a bit grainy. Videos are possible with 2K. The front camera also gives good selfies.

However, stabilization occurs only electronically (EIS), not optically. When moving faster, images blur more quickly, which is especially evident in video recording, which is only possible at a maximum of 2K at 30 fps. In darkness, there is also a lot of image noise.

The secret star of the outdoor dwarf is the FLIR thermal imaging camera. Its resolution is 160 × 120 pixels and it reflects heat differences using different color profiles, which you can select in the corresponding Flir app. Thermal sensitivity is a very good 50 mK and covers temperatures up to 400 °C.

One of the greatest features of Flir cameras is MSX (Multi-Spectral Dynamic Imaging). Image processing techniques combine the color representation of temperature with the structural details of a normal camera image. This makes shapes in thermal images clearer and easier to see, making analysis and interpretation easier.

One of the biggest weaknesses of outdoor cell phones is the weak processor that is used. The Ulefone Armor Mini 20T Pro is no rocket, but thanks to the MediaTek Dimensity 6300, it offers decent performance compared to other robust phones. The system responds instantly and saves the user from painful pauses for thought. With around 10,500 points on PCMark, it’s in the healthy midfield. It’s not just for demanding gaming, as 3Dmark shows only 1300 points in Wild Life.

Despite its compact dimensions, the Mini 20T Pro offers a very generous 8GB of RAM and 256GB of storage (UFS 2.2). Expansion via microSD card is possible, but this comes at the cost of dual SIM usage, which is then not possible. It also has 5G – which isn’t a given for outdoor cell phones. Less contemporary, but common in this price range, are USB-C 2.0 and Wi-Fi 5. There is also Bluetooth 5.2, NFC, and an infrared port.

The existing connection of 3.5 mm jack for wired headphones is now a rarity on smartphones. You’ll also need this if you want to use the integrated FM radio. The fingerprint reader in the power button works fast. We also had fun with the alarm function in the editorial department, which you trigger through the app. Then, like an American patrol car, blue and red lights come on – with a siren sound if desired.

Ulefone offers the Armor Mini 20T Pro with Android 14 and its own user interface, which is based on vanilla Android with an app drawer and menu navigation. Unfortunately, the security patch is out of date and dates back to August 2024. Ulefone is unlikely to provide regular updates including OTA upgrades to the next Android version.

Despite the compact form factor, the smartphone offers a 6200 mAh battery, which also explains the thickness of the device. This ensures a long battery life, which should last up to two days in everyday life. In the PCMark battery test, the device achieved 18 hours of continuous operation. A power supply with a charging power of 33 W is included. This means that the device can be charged from 20 to 100 percent in just less than an hour. Wireless charging is also possible with a power of around 15W.

The Ulefone Armor Mini 20T Pro scores points as a compact outdoor smartphone with a sturdy design, 5G, and a powerful FLIR thermal imaging camera. It offers solid features including a large battery, 90Hz display, and good performance for everyday applications. The camera delivers good results in daylight, but shows weaknesses in darkness and video recording.

It is therefore suitable for outdoor enthusiasts, businessmen and professionals who need a thermal imaging camera and value compactness. The biggest vulnerabilities include outdated security patches and low update possibilities. Additionally, the display is not always easy to read in bright sunlight. The small screen is a challenge for people suffering from presbyopia.

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