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Fenix ARB-L18-3400U Built-in USB 18650 Rechargeable Battery. The Fenix ARB-L18-3400U is a high-capacity 18650 Li-ion USB rechargeable battery with a protection circuit in the anode to help prevent short circuits, overcharge/discharge, and overheating. This battery has its own micro-USB charging port for quick/easy charging without the need for a separate charger. The battery also includes pressure relief vents that expel waste gas in the rare case of an internal short circuit preventing an explosion.

Fenix ARB-L18-3400U Built-in USB Rechargeable Battery Specs:

• Micro-USB charging port
• 3450mAh high capacity
• Protection circuitry to prevent short circuits
• Pressure vents to prevent explosions
• 500 charge cycles
• Voltage: 3.6V
• Charging Current: Recommended 1A, maximum 2A
• Charging Current USB Port: 1A
• Weight: 1.76 ounces (50g)
• Size: Length: 2.76" (70mm) Diameter: 0.73" (18.6mm)
• Warranty Period: 12 months from date of purchase
• Indicator light on battery is red while charging, blue when charged