realme has showcased a smartphone with a massive 15,000mAh battery at the 828 Fan Festival 2025 online event. The company also noted that the phone is 42% slimmer at just 8.89mm and 68% lighter compared to a power bank of the same capacity.
Realme achieved this by using new battery materials, high energy density, and advanced design. This phone is the world’s first phone to feature an all-silicon content anode battery with 25% silicon content. It offers the world’s highest battery energy density of 1200Wh/L. The battery is just 6.48mm thick, and the phone itself measures 8.89mm.
Thanks to this innovation, the phone promises long-lasting performance. On a single charge, users can get up to 18.45 hours of video shooting, 30 hours of gaming, or 50 hours of video playback. The phone can last up to 5.18 days of use and even up to 3 months on standby in airplane mode.
Apart from the battery, the smartphone also comes with strong hardware. It features a 6.7-inch OLED display, MediaTek Dimensity 7300 chipset, 12GB RAM, and 256GB storage. The teaser also confirmed 80W SuperVOOC fast charging. This device looks similar to the earlier realme concept phone with a 10,000mAh battery.
Alongside the big battery phone, realme also introduced the Chill fan phone, which it calls the world’s first “AC phone.” This device uses 7700mm² VC cooling, fan-based heat dissipation, and TEC (Thermoelectric Cooler) technology. A tiny semiconductor reduces the phone’s core temperature by up to 6º C, offering 2 to 3 times better cooling compared to traditional VC systems.
The phone also features a special IceSense Ultra design. When the phone cools from 45 °C to 38 °C, the back panel shifts its color gradient from white to blue. In tests with a popular anime strategy game at full FPS, the phone achieved up to a 6.2 °C temperature drop.
realme has not confirmed when the Chill fan phone will go into mass production. The 15,000mAh battery phone also seems more like a concept for now. However, based on earlier reports, the 10,000mAh battery phone could arrive in the market as early as 2026.
