The USB Power Test App first negotiates a power contract for every PDO supported by the Anker charger, and increases the load gradually to find the threshold where over current protection (OCP) kicks in and voltage and current start to drop for safety reasons.
The USB Power Test App reports out all the PDO's supported by the Anker charger and their OCP thresholds. OCP thresholds for the charger are set at about 13-42% above the maximum current levels for the fixed PDO's.
PDO#1 Fixed: 5V 3A
PDO#2 Fixed: 9V 3A
PDO#3 Fixed: 15V 2A
PDO#4 Fixed: 20V 1.5A
The USB Power Test App from Granite River Labs takes this data to produce an I-V curve which graphically shows the relationship between voltage and current for each PDO. We can observe as the current increases beyond the OCP threshold, the voltage immediately shuts off.
The USB Power Test App can also use the Granite River Labs USB Power Delivery Compliance C2 Tester integrated with the GW Instek APS-7100 programmable AC power supply to compare the charger's power output vs power input so that power efficiency can be measured and compared to regulatory limits from United States of Energy (DOE) Level VI or European Union's CoC Tier 2 requirements. We can repeat the power efficiency tests for different PDO's, current load conditions, and different AC input ranges, allowing us to get a complete picture of power efficiency ranges across all different usage scenarios.
Using the USB Power Test App and FLIR thermal imaging tools, we measured the heat emitted by the Anker PowerPort Speed PD 30 as seen in the following temperature readings and traces for the highest 20V, 1.5A PDO. The max temperature was observed at 66.77 degree Celsius, while it took ~1 hour and 24 minutes for the Anker charger to fully discharge at 30W.