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Free shipping on orders over $75!

Weltool UB21-50 21700 USB Rechargeable Li-ion Battery

Original price $ 26.50 - Original price $ 26.50
Original price
$ 26.50
$ 26.50 - $ 26.50
Current price $ 26.50

Free shipping for orders over $75. Any order containing lithium batteries is at risk of abnormal shipping delays.

Weltool UB21-50 21700 USB Rechargeable Li-ion Battery

 ***Batteries purchased without any equipment they can operate must be shipped with UPS ground shipping. If you purchase only batteries and no flashlights/headlamps you must select UPS Ground unless your order is above the free shipping threshold even if other options are available. The battery label may differ from listing in the picture and there may be scuff marks on positive/negative end from being inside of flashlight during shipment to us.***



  The traditional Li-ion battery with a protective plate is the nickel plate connection method for the negative protection circuit, while the Weltool UB21-50 uses the built-in protection circuit in the battery positive technology, the steel shell is riveted and integrated with the battery core, effectively avoiding short circuit caused by collision or wear and so on. and will not increase the battery diameter and it does not increase the battery diameter.

    The Type-C USB charging interface is set in the positive protection circuit. It can be connected to the USB charging cable to connect the 5V adapter to charge the battery directly or the USB interface of the computer with high current output. It can also be connected to the mobile power source to charge the battery. You can also put the battery into the charger in the Charging; there is a charging indicator on the battery to indicate the charging status.

    Selected 21700 Li-ion battery cells, low internal resistance, high capacity, large discharge current; the battery has triple overheat protection: pressure safety valve protection, diaphragm micro hole protection, PTC cathode blocking protection, and positive protection circuit with four protections: Overheat protection, overcharge protection, over-discharge protection, and short circuit protection. The battery positive cap is raised. It is used in the flashlight to contact the positive spring or the PCB contact surface is tighter. Single or multi-cell batteries can be used at the same time. The robust surface labeling process makes the battery protected, safer, and more reliable!

  • Model: UB21-50
  • Capacity: 5000mAh
  • Internal resistance: ≤50mΩ
  • Voltage: 3.6V
  • Continuous discharge current : 14.5A(10-25 ℃)
  • Charging current: 2A (Type-C USB interface charging current), 3.4A (Max. charger charging current)
  • Overcharge protection voltage: 4.25±0.05V
  • Over-discharge protection voltage: 2.5±0.1V
  • Cycle charge and discharge times: 300 times, the battery has 80% capacity
  • Charging indicator: red light (charging), blue light (charged)
  • Charging temperature: 0-45 ℃
  • Discharge temperature: -20-55℃
  • Storage temperature: -20-55℃
  • Dimensions: 21.4±0.2 mm (diameter), 76±0.2 mm (length)
  • Weight: 73±0.5g
by Weltool

Customer Reviews

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T
Thomas E.
Top-notch cell.

Run time with this cell is fantastic! Highly recommend for protected, button-top applications.