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.
Package included:
3 x Battery Shield
6 x Normal pin
6 x Normal pin
