Description:
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 completed
4. Red LED, lights when charging

Package include:
4 PCS D1 mini Charging board