Blackcell Bu2 Usb Charger

The BU2 is a smart USB charger, which is compatible with most cylindrical rechargeable batteries on the market. The integrated 2A charging port is fast charge capable.


The BU2’s USB output function allows the charger to be used as an external charging station whilst the automatic detection system can detect Li-ion, Ni-MH and Ni-Cd batteries as well as selecting the best charging mode for each battery. The BU2 has three LED display lights, which clearly display the current charging operations.


Input Voltage DC USB5V 2A
Output Voltage 1.42V+0.05V, 4.2V+0.05V
Output Current 500mA*2/1000mA*2/2000mA*1
Output USB 5V/1000mA
Charging Mode constant current and constant voltage
Size 111mm*46mm*32.5mm
Weight 60g (charger only)
Compatible with IMR/Li-ion: 26650 22650 18650 18400 18350 17670 17500 18340 14500 10440 21700, 20700 Ni-MH/Ni-Cd: AA, AAA, AAAA, C
Input type USB

USB Output

  • USB output load voltage: 4.90-5.30V
  • Output current: 1000mA
  • Floating current: <1mA
  • When load current is 1000mA, USB output voltage is 4.75-5.25V
  • Cutoff output protected voltage: 3.0±0.1V


  • Compatible with Li-ion, Ni-MH and Ni-Cd rechargeable batteries.
  • 5V/1000mA USB automatic identification output, as standard.
  • Two independent, micro-controlled charging slots allow for simultaneous charging.
  • Battery type and status automatically detected.
  • Select the appropriate voltage and charge mode.
  • Features reverse polarity and short circuit protection.
  • Integrated overcharging, overheating, overvoltage, overcurrent, and discharge protections.
  • Optimally designed for heat dissipation.
  • Certified by CE, RoHS, and FCC.
  • 3 LEDs display the charging status. (30% 70% 100%)
  • When no batteries are installed, the three LEDs will flash and then off one after the other when the charger connected to a power source.
  • When a faulty battery is inserted, the three LEDs will flash at the same time to alert you.
  • During the charging process, the three LEDs light up one by one, and will all remain light up until the charging is completed.
  • 1A or 2A input, Intelligent chip, automatically stop charging when batteries are fully charged.
  • Fully charged testing: -DV, 0DV testing charging time controlling, maximum voltage testing.


  • The product is for use specifically with Lithium, Ni-Cd and Ni-MH batteries only. Charging other batteries can potentially lead to an explosion, broken or leaking batteries, personal injury or property damage.
  • Incorrect use of the charger may lead to an electric shock.
  • The BU2 charger should only be used indoors or inside a vehicle. Under no circumstances should it be exposed to water, high humidity, and low or high ambient temperatures.
  • Do not disassemble or modify the charger.
  • Please use appropriate AC voltage 100-240V.
  • No BlackCell products are intended for use by anyone under the age of 18.
  • The safe operating temperatures are between 0°C-35 °C 32°F-95°F.
  • Do not drop or rest heavy items on the unit.
  • If any problems arise with either the batteries or charger, unplug the power cord immediately.


The BU2 Charger can be exchanged for a replacement by authorized distributors within 180 days of purchase, should any issues arise.

The warranty is invalid in any situation below:

  1. The product(s) is/are broken, reconstructed and modified.
  2. The product(s) is/are damaged by leakage of batteries.
  3. The product(s) is/are damaged by improper use.