The UltraFire 21700 flashlight offers even more power and extended battery life. With a robust, rechargeable 21700 battery, it delivers brighter light and longer runtime. Built tough for outdoor adventures and emergencies, it’s compact, durable, and equipped with multiple brightness modes for versatile use.

21700 Flashlight

 
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​​21700 Flashlights: High-Performance Illumination for Modern Needs​​

A. ​​Superior Battery Capacity & Energy Density​​

21700 flashlights utilize lithium-ion batteries measuring ​​21mm in diameter and 70mm in length​​, offering ​​4,000–5,000mAh capacity​​ and ​​20–30% higher energy density​​ compared to 18650 cells. This translates to extended runtime (e.g., ​​12+ hours on medium modes​​) and compatibility with high-power LEDs​​, which deliver ​​2,000–5,200 lumens​​ for tasks like search-and-rescue or outdoor exploration.

B. ​​​​Rugged Design & Adaptive Features​​

Premium models like the ​​UltraFire T5​​ feature ​​IPX8 waterproofing​​, ​​aircraft-grade aluminum alloy bodies​​, and ​​thermal regulation systems​​ to prevent overheating during prolonged high-brightness use. 

Frequently asked questions

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Q1: ​​​​Can I use 18650 batteries in a 21700 flashlight?​​

A: Yes, with adapters. Most 21700 flashlights (e.g., ​​UltraFire UF-806​​) support 18650 cells, though runtime and brightness may drop by 15–20%.

Q2: ​​​​What makes 21700 better than 18650?​​

A: Higher capacity (​​5,000mAh vs. 3,500mAh​​), superior discharge rates (​​70A continuous​​), and longer lifespan (​​500+ cycles​​).

Q3: ​​​​Do they work as power banks?​​

A: Select models (e.g., ​​UltraFire UF2) include ​​USB-C power bank functionality​​ to charge phones or GPS devices.

Explore by UltraFire Lighting Product Category

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