Blackcell BU1 USB Charger

The BU1 is a smart USB charger, which is compatible with most cylindrical rechargeable batteries on the market. The integrated single 2A charging port is fast charge capable.


The BU1’s integrated USB output function allows the charger to be used as an external charging station. The BU1’s automatic detection system can detect Li-ion, Ni-MH and Ni-Cd batteries whilst also selecting the charging mode for each independent battery. The BU1’s three LEDs clearly display the current charging operations.


Input power supply Micro USB DC5V 2A
Output Voltage 1.48V, 4.2V±0.01V
Output USB 5V/1000mA
Output current 2000mA/1000mA/500mA
Constant voltage cutoff current <100mA
External power supply standby current <15.0mA
Size 111mm*38mm*32mm
Weight 58.5g(Charger Only)
Compatible with IMR/Li-ion: 20700,21700, 26650, 22650,18650,18490,18350,17670,17500,16340(RCR123),14500,10440 Ni-MH/Ni-Cd: AA,AAA,AAAA,C
USB Output
  • USB output voltage: 4.90-5.30V
  • Output current: 1000 mA
  • Floating current <1mA
  • When the load current is at 1000mA, the USB output voltage is:between 4.75-5.25V
  • Cutoff output voltage:3.0±0.1V

Button and LED

  • Keep the button pressed for 2 seconds to switch the charging current from 1000mA to 2000mA.
  • All LEDs will light up when the charger connected to a 5V power supply. If no Batteries are inserted, the LEDs will turn off.
  • Batteries are automatically detected by type and will start charging once inserted. The LEDs will flash, showing the battery‘s current power.
  • Without the power cable connected, insert a battery to check the remaining charge. (LED will turn off within 5 seconds, press button once to display once more)
  • USB output: The power indicator light will stay lit for 10 seconds after a battery is connected.


  • Micro USB, DC 5V input,,Micro-controller management system.
  • 1000mA /2000mA for Li-ion battery, and 500mA for Ni-MH batteries.
  • LED display charging status 30%, 70%, 100%.
  • Battery type (Ni-MH and Ni-Cd 1.2V Li-ion 3.7V)
  • Automated detection of Li-ion and Ni-MH batteries.
  • 0V voltage activation capabilities. Trickle charge will be enabled when the battery voltage is below 1.65-1.85V.
  • Integrated overcharging, overheating, overvoltage, overcurrent, and discharge protections.
  • Faulty battery and reverse polarity protection.
  • Charging mode: constant current and voltage
  • DC input, the power supply is 5V 2A (Micro plug).
  • Automatically detect USB 5V/1000mA output.
  • Certified by CE, ROHS, and FCC.


  • 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 BU1 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 an appropriate AC voltage 100-240 V.
  • 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 warranty is void in any situation below:

The BU1 Charger can be exchanged for a replacement by authorized distributors within 180 days If there are any product issues.

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