Quickpost: iPad Pro Charging – Power Consumption

Didier Stevens

Jul 31

I charged an iPad Pro (12.9 Inch) and measured the power consumption (at 120V and 230V). According to the specs, this iPad has a battery with a capacity of 40.88 Wh.

Procedure: when the iPad Pro turns itself of because of a low battery, I started to charge the iPad with an Apple A2347 USB C charger and measured the AC power consumption of this charger. It consumes around 21 Watt, this value starts to diminish when the battery approaches full charge. When at 100%, the charger will still deliver power, slowly decreasing to 3 Watts, and then it stops delivering power for charging. At that point, I stop the power consumption measurement.

I did not use the iPad while charging.

This measurement was done twice: at 120V 60Hz and 230V 50Hz (using an AC power supply).

AC	Wh	Duration
120V 60Hz	57.171	03:07:48
230V 50Hz	57.559	03:09:16

There's not much difference between the two measurements, but what I'll certainly take away from this test, is that it takes around 57 Wh of AC power to charge a 40.88 Wh battery!