Microduino-BM is a discharging module which combines a single-cell Li-ion battery charge management, power detection and LED indication. The output voltage is 5V, and LDO is 3.3V output, providing the outstanding battery management for the Microduino-Core module.

• Support UPS;
• Integrate lithium battery charge/discharge management, power detection, 5v output, 3.3v LDO;
• Small, cheap, stackable, open;
• Uniform Microduino interface standard and rich peripheral modules, capable of having a fast and flexible connection and extension with other modules and sensors in accord with Microduino interface standard;
• 2.54-pitch row female connector for easy integration into pegboards.

• A two-notch toggle switch to control the output voltage (5v and 3.3v);
• A MicroUSB interface for power charging.
• A 1.27-pitch battery interface;
• UPIN27 contains the 5V, 3V3 and GND interface; (The analog voltage detection of BM can be selected between A6 and A7, and the digital low voltage will be output to D2 interface. Please don’t rely protection circuit to protect the battery, which only works in extreme circumstance. You can use mcu to detect the voltage of the battery and then judge the battery’s charge. )
• Charging
  Plug in MicroUSB and charge the lithium battery with the current of 600ma.
  The indicator goes on when charging and goes out after finishing.
• Discharge
  When you plug in MicroUSB, the 5v or 3.3v voltage is powered through MicroUSB. Otherwise, the voltage will be supplied by the lithium battery. Meantime, you need to pull the power output switch to “ON”. If it is not started, please plug in MicroUSB to activate and then try again.
  The indicator goes on when there is electricity output, otherwise, it goes out.
  5V offers 1a electricity output and 3.3V offers 700ma output.

• Wiki