Nitecore UM20 USB Charger

Nitecore UM20 USB Charger

Nitecore UM20 USB Charger

UM20 is the latest innovation from Nitecore that is a USB powered Li-ion battery charger. It is compact, fully automated with clear digital display of detail charging status and charges many different type Lithium Ion rechargeable batteries.

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  • USB powered Li-ion battery charger
  • High definition LCD displays real time charging status
  • Features USB output charging
  • Integrated intelligent power management system
  • Intelligently detects input power
  • Intelligently distributes charging power
  • Priority Mode offers either battery or USB charging
  • Enables data transfer via USB
  • Intelligently selects charging current based on battery capacity
  • Features rear USB cable winder and grooves to accommodate 2.5mm/3.0mm USB cables
  • Constructed from fire retardant materials
  • Features reverse polarity protection
  • Designed  for  optimal  heat dissipation
  • Certified by RoHS, CE, FCC and CEC
  • Insured worldwide by Ping An Insurance (Group) Company of China, Ltd.


  • Input voltage: Micro USB DC 5V
  • Output voltage:   4.2V ±1% / 5V
  • Output current:   1000mA / 500mA
  • Input current:      ≥500mA
  • Compatible with:
  • Li-ion / IMR: 18650, 18490, 18350, 17670, 17500, 16340(RCR123), 14500, 10440
  • Dimensions: 3.94”×2.20”×1.38” (100mm× 56mm×35mm)
  • Weight:    2.72oz (77.2 gram)(without batteries or power cord)

Standard Function

  • Connecting: Unwind the USB cable, lift the rear panel and draw out the cable as instructed. Plug one    end of the included USB cable to the UM20’s input port and the other end to a power supply (adapter,     PC or other standard USB output port). Upon powering up, the UM20’s LCD will display the power        level indicator (hollow) and battery percentage (0%).
  • Inserting Batteries: Insert batteries as instructed. Incorrectly inserted batteries will prevent the UM20   from functioning.
  • Battery Test: After battery installation, the UM20 will run a quick battery test before charging.  If  a problem is detected (for example the batteries are installed backwards), the UM20 will stop charging    and display “EE” on the LCD to notify the user.
  • Charging: During the charging process, charging current will  adjust  automatically  based  on  the detected battery type, power level and internal  battery  resistance.  For  example,  when  charging batteries of smaller capacities such as 14500 and 16340, charging current will automatically be set to 500mA, ensuring safe use and preserving battery longevity.
  • Charging Progress: The UM20 will indicate battery status and charging progress. When batteries are   fully charged, 5 power level indicator bars and “100%” will illuminate steadily on the LCD display.

Package included:

  • 1 x Nitecore UM20 USB Power Battery Charger
  • 1 x USB port
  • User Manual

Charger Safety Warning: 

Nitecore recommends using only quality USB adapters with the UM20. Using poor quality adaptors   may result in the LCD displaying “EE” to indicate an error.

The charger is restricted to charging Li-ion, IMR rechargeable batteries only. Never use the charger    with other types of batteries as this could result in battery explosion, cracking or leaking, causing  property damage and/or personal injury.

The safe operation temperature for the charger is between -10 to 40°C, and the safe storage temperature is -20 to 60°C.

Do not use the charger to charge other unspecified batteries as they may leak or burst, causing personal injury and damage.

Observe polarity diagrams located on the charger. Always place the battery cells with positive tip facing the top.

Never leave the charger unattended when it is connected to power. If any malfunction is found, terminate the process at once and refer to the operation manual.

The charger is for use of adults above 18 years old. Children under this age must be supervised by an adult when using the charger.

Please make sure the correct program and settings are chosen and set. Incorrect program or setting   may damage the charger or cause fire or explosion.

Never attempt to charge primary cells such as Alkaline, Zinc-Carbon, Lithium, CR123A, CR2, or any other unsupported chemistry due to risk of explosion and fire.

Do not charge a damaged IMR battery as doing so may lead to charger short-circuit or even explosion.

Never charge or discharge any battery having evidence of leakage, expansion/swelling, damaged outer wrapper or case, color-change or distortion.

Do not expose the device to direct sunlight, heating devices, open flames; avoid extreme high or extreme low ambient temperatures and sudden temperature changes.

Please operate the charger in a well-ventilated area. Do not operate or store it in damp area. Keep       all the inflammable volatile substances away from operating area.

Avoid mechanical vibration or shock as these may cause damage to the device.

Do not short-circuit slots or other parts of the device. Do not allow metal wires or other conductive material into the charger.

Do not touch hot surfaces. The rechargeable batteries or the device may become hot at full load or   high power charging/discharging.

Do not overcharge or over discharge batteries. Recharge drained batteries as soon as possible.

Remove all batteries and unplug the charging unit from the power source when not in use.

Opening, disassembling, modifying, tampering with the unit may invalidate its guarantee, check warranty terms.

Do not misuse in any way. Use for intended purpose and function only.