WeMos D1 Mini Battery Shield Lithium Battery Charging Boost With LED Light Module Mini Micro USB Interface For WeMos D1 Mini You can use D1 mini without usb cable, it's really wireless now. Put D1 mini anywhere, using this battery shield and a lithium Battery. Boost, just connect lithium Battery to this shield, power supply for the entire D1 mini system Charging, when the battery run out, you do not need to unplug the battery, just using usb port to charging. 1. Connect to lithium Battery (normal 3.3-4.2V) 2. Charging port (normal 5V)3. Green LED, lights when charging is completed4. Red LED, lights when charging Shipping list: 1.Normal pins x2pcs