一度电能给iPhone完全充电几次？

W1=1度=1kW·h=1000w·3600s=3600000J1mAh=0.001A·3600s=3.6CW2=Pt=UIt=3.7V·1420mA·1h=3.7V·1.42A·3600s=18914.4Jn=W1/W2=3600000J/18914.4J=190.33190次，损耗10%。