Fenix ARB-L21-5000U Rechargeable 21700 Battery

The Fenix ARB‑L21‑5000U is a high-capacity 21700 rechargeable Li‑ion battery delivering 5,000 mAh of reliable power for high-drain flashlights and gear. Equipped with a built-in USB‑C charging port, you can recharge it quickly with common USB‑C cables—no separate charger required. Ideal for extended runtime and convenience. Safety is front and center: it features comprehensive protection circuitry (overcharge, over-discharge, short-circuit, and overheat protection), as well as pressure relief vents for safe energy release. The button-top design ensures compatibility with a wide range of devices. Rated for 500 charge cycles, it maintains dependable performance over time. Key Specifications: Capacity: 5,000 mAh, Nominal Voltage: 3.6 V Charge Rate: USB‑C port, up to 5 A max (standard 1–2 A recommended) Output: Up to 8 A discharge Safety Features: Multi-layer protection circuitry, pressure relief vents Longevity: Up to 500 full charge cycles Design: Button‑top format, 73 mm long, ~21.6 mm