Redmi K90 Ultra packs a literal cooling fan and a massive 8,550 mAh battery
Xiaomi launched the Redmi K90 Ultra in China on June 30, 2026 — a gaming phone with a built-in cooling fan, an 8,550 mAh battery, and a starting price of roughly $410. That combination is unusual even by gaming-phone standards, where large batteries and serious cooling hardware typically push prices well past the $700 mark. If Xiaomi brings it to the US or UK, it could seriously undercut rivals like the ASUS ROG Phone and RedMagic series.
The fan inside
The phone runs on Qualcomm's Snapdragon 8 Elite paired with Xiaomi's own D2 graphics co-processor. The chip is fast, but it runs hot — mainstream flagships using the same silicon can drop 30–50% in sustained performance after just 15 minutes of heavy use, per GSMArena. Xiaomi's answer is an active cooling fan built directly into the chassis, alongside a large vapor chamber. The company claims the fan drops chip temperature by 10°C within 100 seconds. Memory is LPDDR5X Ultra and UFS 4.1 storage — the fastest options currently available.
The screen and build
The display is a 6.83-inch OLED panel at 1.5K resolution with a 165Hz refresh rate and 3,500-nit peak brightness — bright enough to use outdoors in direct sunlight. An aluminum frame keeps the chassis rigid. One gamer-specific touch: you can set different touch sensitivity levels for separate areas of the screen, useful for shooters where precise thumb placement matters.
Battery and charging
The 8,550 mAh battery is notably large — most flagships sit between 5,500 and 7,000 mAh. Wired charging tops out at 100W, and the phone also supports 22.5W reverse wireless charging, so you can top up earbuds or a friend's device directly. For gaming sessions, Redmi includes bypass charging, which routes power directly from the charger to the processor and bypasses the battery entirely. That keeps heat down during long play sessions and reduces long-term battery wear. The OnePlus N6, launched in China around the same time, also includes bypass charging — but it lacks the active fan and the larger battery.
Protection, cameras, and price
Despite the gaming focus, the K90 Ultra carries IP66, IP68, and IP69 ratings — IP69 means it can handle high-pressure, high-temperature water jets. Stereo speakers are tuned by Bose, and an ultrasonic fingerprint sensor sits under the display. The main camera uses a 50MP sensor; a full multi-camera breakdown hasn't been confirmed yet.
Chinese pricing breaks down as follows:
- 16GB / 256GB — CNY 3,000 (~$410) - 12GB / 512GB — CNY 3,550 (~$485) - 16GB / 512GB — CNY 3,800 (~$515)
US and UK pricing and availability haven't been announced. Based on typical Xiaomi timelines, a global rollout — if it happens — is likely 6–12 weeks behind the China launch, confirms 91mobiles.