The Fenix 21700 4000 mAh (ARB-L21-4000P) high-current rechargeable batteries with protected electronics are designed for discharge current up to 18 A. Li-ion rechargeable batteries are characterized by very high capacity, do not suffer from memory effect or self-discharge. Li-ion in size 21700 are the best choice in terms of stored energy due to the size and weight of the battery, and are gradually gaining ground in the automotive industry.
Fenix battery protection consists of internal safety mechanisms and protective electronics. Added electronic circuits prevent the cell from overcharging, over-discharging and against short-circuiting or excessive current draw. If the battery electronics assess that the limits have been reached, they safely disconnect the cell.
Internal protection consists of a separator, state-of-the-art Positive Temperature Coefficient (PTC) overheat protection and a special anti-blast valve. In the event that the gas pressure in the cell exceeds a certain limit, the internal separator separates the electrodes inside the battery and thus de-facto interrupts the exothermic reaction and the anti-blast valve releases the excess gas pressure outside the battery. The combination of electronic and mechanical (temperature and pressure) protection makes Fenix batteries among the safest Li-ion batteries available.
This battery is designed specifically for use in the Fenix LR35R LED flashlight. It can also be used, for example, in Fenix HT18, PD36R, PD36 TAC, PD40R, TK16 V2.0, TK20R V2.0, TK22 UE, E35 V3.0 and C7. However, it cannot be used in 18650 battery flashlights due to its larger size!
Due to the 76 millimeters length of the battery (including protective electronics), it can only be charged in chargers that are adapted to this length. See recommended chargers below.
Fenix 21700 4000mAh battery specifications
- Nominal voltage : 3.6V
- Capacity : 4000 mAh, tested at 0.2 C discharge current with termination at 2.5 V and 25°C
- Maximum current draw: 18 A (max. for 3 minutes, 10 A over long periods)
- Maximum charging current: 4 A
- Dimensions: 21.5mm (diameter) x 76mm (length) (+/- 0.5mm)
- Weight 70 grams
- Overcharge, full discharge and short circuit protection (>18 A). Protective circuit attached to the plus pole.
- Lifetime of more than 500 charge cycles
- Recommended operating temperatures: 0-45°C (charging), -20 to +60°C (discharging)
- Scope of delivery: one piece of Fenix 21700 4000mAh battery (ARB-L21-4000P).
Recommended chargers
Due to the length of the battery 76 millimeters (including protective electronics), it can only be charged in chargers that are adapted to this length and are listed below. It will not fit in other models.
Fenix ARE-X1 V2.0 Charger
Fenix ARE-A2 Charger
USB charger Fenix ARE-D1
USB charger Fenix ARE-D2
Fenix ARE-A4 charger
USB Charger FC2
USB charger SC1
Eight channel USB charger VC8
Warning
- Do not discharge the battery below 2.5V if possible
- Do not short-circuit the battery (do not connect the cell poles with a wire)
- Do not throw the battery into fire or water
- Do not insert the battery into the charger in reverse (opposite polarities)
- When using the battery, observe safety guidelines
- Use only an adequate charger that supports Li-ion batteries
Warranty
Warranty two years.
