Fenix ARB-L21-5000U Rechargeable Battery

(19 customer reviews)

$34.00 $24.95

SKU: ARB-L21-5000U Category:

ARB-L21-5000U is a high capacity 21700 Li-ion USB rechargeable battery built for more power and longer runtimes. This battery has its own micro-USB charging port for quick/easy charging without the need for a separate charger. Additional features include a protection circuit in the anode to help prevent short circuits, over charge/discharge and over heating. Pressure relief vents which expel waste gas in the rare case of an internal short circuit preventing an explosion. Battery capacity up to 5000mAh. 500 charging cycles. This product will only work in those models supporting 21700 batteries. Currently recommended for the HT18, PD36R, TK22 V2.0, and TK22 UEA USB-C charging cord is NOT included. Important Note: THIS BATTERY IS NOT COMPATIBLE WITH 18650 FLASHLIGHTS OR OLDER STYLE CHARGERS. COMPATIBLE CHARGERS ARE THE ARE-A2ARE-A4ARE-D1 OR ARE-D2.

For commercial orders and large purchases, contact us at (888) 775-9996 x6, or
WARNING. Be aware of counterfeit Fenix merchandise in the U.S. marketplace.


  • 5000mAh high capacity
  • USB Type-C rechargeable battery
  • Protection circuitry to prevent short circuits
  • Pressure vents to prevent explosions
  • 500 charge cycles
  • Indicator light on battery is red while charging, blue when charged

Capacity: 5000mAh
Voltage: 3.6V
Charging Current: Recommended 1A, maximum 5A
Weight: 2.6 ounces (72.5g)
Size: Length: 2.99″ (76mm) Diameter: 0.85″ (21.5mm)
Warranty Period: 12 month from date of purchase

19 reviews for Fenix ARB-L21-5000U Rechargeable Battery

5 star
4 star
3 star
2 star
1 star
Powered by Customer Reviews Plugin
Showing 17 of 19 reviews (5 star). See all 19 reviews
  1. Chris B. (verified owner)


    Was this review helpful to you?
  2. Nickolas F. (verified owner)

    I have been using this battery with the PD36R for a few weeks now. I use it nearly every evening when I take the dog for a walk as I live in the woods, probably for 15 to 20 minutes at a time at a lower setting. I fully charged the battery when it first arrived, and I haven’t needed to plug it in again since. By contrast, my old Mag light would go through D cells at the rate of 2 every couple weeks on the same walking path, and those were not rechargeable!

    Was this review helpful to you?
  3. Alan Horne (verified owner)

    I am still (2 weeks) on the 1st battery!
    Incredible staying power.

    Was this review helpful to you?
  4. Tracy A. (verified owner)

    Love it

    Was this review helpful to you?
  5. Jon Cortez (verified owner)

    Great product so far!

    Was this review helpful to you?
  6. John Poggi (verified owner)

    once again, batteries are awesome

    Was this review helpful to you?
  7. Jay (verified owner)

    so sick. battery lasts forever

    Was this review helpful to you?
  8. arthur (verified owner)


    Was this review helpful to you?
  9. Anonymous (verified owner)


    Was this review helpful to you?
  10. Rafael (verified owner)

    Excellent service very fast process and the product is of excellent quality. I highly recommend these products

    Was this review helpful to you?
  11. Jerry Robbins (verified owner)

    Great battery.

    Was this review helpful to you?
  12. Bruce Baumel (verified owner)

    Excellent Fenix product

    Was this review helpful to you?
  13. Mitchell (verified owner)

    I’m generally not for rechargeable batteries, but in this instance I took a chance and am not disappointed.

    Was this review helpful to you?
  14. John Petersen (verified owner)

    Fantastic battery that offers long run times and tells you when it’s fully charged.

    Was this review helpful to you?
  15. Kenneth (verified owner)

    Wonderful batteries!

    1 out of 1 people found this helpful. Was this review helpful to you?
  16. Rod F. (verified owner)

    Great life

    Was this review helpful to you?
  17. George Robinson (verified owner)

    Love it!

    Was this review helpful to you?
Add a review

Your email address will not be published. Required fields are marked *

You may also like…