Fenix Battery ARB-L21-5000U 21700

The ARB-L21-5000U is a professional 21700 Li-ion battery with an impressive 5000 mAh capacity, delivering approximately twice the energy of traditional 18650 models. This translates to significantly extended runtime for tactical flashlights, headlamps, and similar equipment—ideal for professionals who depend on reliable illumination in the field, including hunters, law enforcement, and rescue personnel operating under demanding conditions. The integrated USB-C charging port sets this battery apart: you charge it directly without requiring a separate charger, much like a portable power bank. The charging process provides clear user feedback—the positive terminal grows warm during charging and cools to room temperature once fully charged, creating an intuitive indicator system. The steel body with riveted construction provides impact protection, while pressure-relief vents prevent internal gas accumulation. Safety is prioritized through multiple protection circuits including overcharge protection, over-discharge protection, short-circuit protection, over-temperature protection, and a pressure-activated safety valve. The PTC thermistor at the negative terminal delivers adaptive protection that remains effective at lower temperatures. Compatible with various Fenix models including the PD36R, TK22 V2.0, TK22 UE, and HT18, this battery supports up to 500 charge cycles, ensuring years of dependable performance. Specifications: 5000 mAh capacity | 3.6 V nominal | recommended charge current 1 A (max. 5 A) | USB output 2 A | maximum continuous discharge 8 A | weight 72.5 g | dimensions 76 × 21.5 mm

Estimated shipping times vary depending on your location and the shipping method chosen. Once your order has been shipped, you will receive a shipping confirmation with tracking information, allowing you to monitor the progress of your delivery.

We aim to process your order within 2-5 business days, unless otherwise stated.