Anker PowerDrive 2 and Satechi 72W Type-C PD Car Charger Adapter

How quickly will Anker and Satechi car chargers drain your battery?

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I’m currently working on a small scale solar home project, with the intention to provide autonomous power supply for phone and occasional laptop charging. The system is based on a 12V Lead-acid battery, and the easiest way to add chargers is to use car cigarette lighter accessories. The issue with those accessories though is that provided specs are often very limited. What interests me the most is standby current and efficiency, but I have never seen these provided in documentation for any cigarette lighter accessory.

Standby current and efficiency are important in estimating how fast battery is going to be drained. Standby current shows consumption of charger itself, when nothing is charging from it. Efficiency shows how much energy is lost during charging.

I got Satechi 72W USB-C and Anker Power Drive 2, and I have, of course, made some measurements.The Satechi charger has one USB-C and one USB-A port. The USB-C port supports 60W Power Delivery, and the USB-A port provides up to 2.4A. The Anker charger has two USB-A ports, with each providing 2.4 A.

To measure the efficiency I have used my Pixel 3 XL phone and XPS 9570 laptop as a load. The CPU-Z utility was very handy to put a 100% load on my laptop’s CPU to make it consume more than 60W. Photos of my test setup and plotted measurements are shown down below. To answer the question, it will take about three months for the Satechi charger to drain an average car battery, while being in standby. The Anker charger will drain you battery in about eight months. The efficiency of both chargers is in the range of 77% to 87%, depending on the conditions.

Anker PowerDrive 2 and Satechi 72W USB-C PD standby current depending on the input voltage
Satechi charger has two to six times larger standby current compared to Anker.

Anker PowerDrive 2 and Satechi 72W USB-C PD standby power depending on the input voltage
Satechi charger has significantly larger standby power compared to Anker.
Anker PowerDrive 2 and Satechi 72W USB-C PD estimated standby energy over time
If left connected for a week, Satechi charger would consume about 54Wh, and Anker about 18Wh.
Satechi 72W USB-C PD efficiency depending on the input voltage and output power
Satechi charger has a decent efficiency of about 85% on average. At 8W@9V ouput, charger works down to 4V input, at 25W@20V down to 9V. I couldn’t measure at any lower input voltage at 60W@20V, because my bench power supply can’t provide more than 5A.
Anker PowerDrive 2 and Satechi 72W USB-C PD efficiency via USB-A ports depending on input voltage
Satechi has slightly lower efficiency compared Anker, when using USB-A port. The comparison, however, is a bit unfair, since power output is not the same.

Octave/Matlab source code

This is the measurement data and source code for plotting the graphs in GNU Octave or MATLAB.

# Standby current Anker
# Turn off 7.1V, turns on 7.5V
# Voltage,V		Current, mA
STB_ANKER = [7.50			7.56;
8.00			7.68;
9.00			7.82;
10.00			8.00;
11.00			8.25;
12.00			8.55;
13.00			8.87;
14.00			9.20;
15.00			9.53;
16.00			9.88;
17.00			10.17;
18.00			10.35;
19.00			10.39;
20.00			10.32;
21.00			10.22;
22.00			10.10;
23.00			9.98;
24.00			9.83;
25.00			9.69 ];

# Standby current Satechi
# Voltage, V		Current, mA
STB_SATECHI = [5.00			10.00;
6.00			15.31;
7.00			17.76;
8.00			20.33;
9.00			22.68;
10.00			24.84;
11.00			26.21;
12.00			27.20;
13.00			28.08;
14.00			28.86;
15.00			29.55;
16.00			30.17];

figure(1)
plot(STB_ANKER(:,1),STB_ANKER(:,2), '-o', 'color', [227/255 82/255 5/255], 'LineWidth', 2);
hold on;
plot(STB_SATECHI(:,1), STB_SATECHI(:,2), '-o','color', [61/255 60/255 56/255], 'LineWidth', 2);
hold off;
grid on;
set(gca,'fontsize',20);
xlabel("Input voltage, V");
ylabel("Standby current, mA");

h = text (15, 13,  "Anker Power Drive 2");
set (h, "fontsize", 20);
set (h, "color", [227/255 82/255 5/255]);

h = text (17, 30.5,  "Satechi 72W USB-C PD");
set (h, "fontsize", 20);

title ('Standby current');
print('anker_satechi_standby_current.png', '-dpng', '-S1000,500');

figure(2)
plot(STB_ANKER(:,1),STB_ANKER(:,2).*STB_ANKER(:,1), '-o', 'color', [227/255 82/255 5/255], 'LineWidth', 2);
hold on;
plot(STB_SATECHI(:,1), STB_SATECHI(:,2).*STB_SATECHI(:,1), '-o','color', [61/255 60/255 56/255], 'LineWidth', 2);
hold off;
grid on;
set(gca,'fontsize',20);
xlabel("Input voltage, V");
ylabel("Standby power, mW");

h = text (17, 250,  "Anker Power Drive 2");
set (h, "fontsize", 20);
set (h, "color", [227/255 82/255 5/255]);

h = text (15, 400,  "Satechi 72W USB-C PD");
set (h, "fontsize", 20);

title ('Standby power');
print('anker_satechi_standby_power.png', '-dpng', '-S1000,500');

STB_DAYS = linspace(0, 7, 8).';

figure(3)
plot(STB_DAYS, STB_DAYS.*12*8.55*(24/1000), '-', 'color', [227/255 82/255 5/255], 'LineWidth', 2);
hold on;
plot(STB_DAYS, STB_DAYS.*27.20*12*(24/1000), '-','color', [61/255 60/255 56/255], 'LineWidth', 2);
hold off;
grid on;
set(gca,'fontsize',20);
xlabel("Days");
ylabel("Standby energy, Wh");

h = text (4, 5,  "Anker Power Drive 2");
set (h, "fontsize", 20);
set (h, "color", [227/255 82/255 5/255]);

h = text (3.2, 21,  "Satechi 72W USB-C PD");
set (h, "fontsize", 20);

title ('Estimated consumed energy during continious standby');
print('anker_satechi_standby_energy.png', '-dpng', '-S1000,500');


#Efficiency Satechi USB-C, laptop as a load, in BIOS
#Input voltage,V 	Input current, A 	Output Voltage, V	Output Current, A
EFF_SATECHI_1 = [9.00				3.458				19.9				1.28;
10.00				3.057				19.9				1.28;
11.00				2.741				19.9				1.28;
12.00				2.487				19.9				1.28;
13.00				2.278				19.9				1.28;
14.00				2.112				19.9				1.27;
15.00				2.088				19.9				1.37;
16.00				1.952				19.9				1.38];

#Efficiency Satechi USB-C, laptop as a load, full cpu load
#Input voltage,V 	Input current, A 	Output Voltage, V	Output Current, A
EFF_SATECHI_2 = [14.00				4.755				19.9				2.88;
15.00				4.408				19.8				2.89;
16.00				4.105				19.9				2.89];

#Efficiency Satechi USB-C, phone as load
#Input voltage,V 	Input current, A 	Output Voltage, V	Output Current, A
EFF_SATECHI_3 = [4.00				2.72				9.03				0.89	;		
5.00				1.94				9.04				0.87;
6.00				1.530				9.06				0.83;
7.00				1.43				9.03				0.94;
8.00				1.18				9.01				0.90;
9.00				1.038				9.02				0.90;
10.00				0.930				9.04				0.89;
11.00				0.853				9.01				0.89;
12.00				0.784				9.04				0.89;
13.00				0.726				9.01				0.89;
14.00				0.678				9.00				0.90;
15.00				0.636				9.03				0.89;
16.00				0.599				9.02				0.90];

figure(4)
plot(EFF_SATECHI_1(:,1), (EFF_SATECHI_1(:,3).*EFF_SATECHI_1(:,4))./(EFF_SATECHI_1(:,1).*EFF_SATECHI_1(:,2)).*100, '-o', 'color', [227/255 82/255 5/255], 'LineWidth', 2);
hold on;
plot(EFF_SATECHI_2(:,1), (EFF_SATECHI_2(:,3).*EFF_SATECHI_2(:,4))./(EFF_SATECHI_2(:,1).*EFF_SATECHI_2(:,2)).*100, '-o', 'color', [61/255 60/255 56/255], 'LineWidth', 2);
plot(EFF_SATECHI_3(:,1), (EFF_SATECHI_3(:,3).*EFF_SATECHI_3(:,4))./(EFF_SATECHI_3(:,1).*EFF_SATECHI_3(:,2)).*100, '-o', 'color', [63/255 171/255 92/255], 'LineWidth', 2);
hold off;
grid on;
set(gca,'fontsize',20);
xlabel("Input voltage, V");
ylabel("Efficiency, %");

h = text (13.5, 88.1,  "P_{out}=60W\nV_{out}=20V");
set (h, "fontsize", 20);
set (h, "color", [61/255 60/255 56/255]);

h = text (9.2, 80.1,  "P_{out}=25W\nV_{out}=20V");
set (h, "fontsize", 20);
set (h, "color", [227/255 82/255 5/255]);

h = text (6, 79.9,  "P_{out}=8W\nV_{out}=9V");
set (h, "fontsize", 20);
set (h, "color", [63/255 171/255 92/255]);

title ('Satechi 72W USB-C PD efficiency at different loads for USB-C port')
print('satechi_usb-c_efficiency.png', '-dpng', '-S1000,500');


#Efficiency Satechi USB-A, phone as load
#Input voltage,V 	Input current, A 	Output Voltage, V	Output Current, A
EFF_SATECHI_4=[
5.0					0.631				4.36				0.61;
6.0					0.577				4.83				0.60;
7.0					0.495				4.83				0.60;
8.0					0.436				4.83				0.60;
9.0					0.391				4.83				0.60;
10.0				0.355				4.84				0.60;
11.0				0.327				4.82				0.61;
12.0				0.302				4.83				0.61;
13.0				0.282				4.83				0.60;
14.0				0.264				4.83				0.60;
15.0				0.249				4.82				0.60;
16.0				0.236				4.82				0.61];

#Efficiency Anker USB-A, phone as load
#Input voltage,V 	Input current, A 	Output Voltage, V	Output Current, A
EFF_ANKER = [7.5					1.048				4.70				1.41;
8.0					0.980				4.71				1.41;
9.0					0.869				4.70				1.41;
10.0				0.783				4.7					1.41;
11.0				0.712				4.73				1.42;
12.0				0.654				4.74				1.41;
13.0				0.605				4.71				1.42;
14.0				0.563				4.72				1.41;
15.0				0.527				4.73				1.41;
16.0				0.496				4.74				1.40;
17.0				0.468				4.75				1.41;
18.0				0.443				4.75				1.41;
19.0				0.422				4.74				1.41;
20.0				0.402				4.74				1.41;
21.0				0.384				4.73				1.41;
22.0				0.369				4.74				1.41;
23.0				0.354				4.75				1.41;
24.0				0.338				4.76				1.41;
25.0				0.320				4.75				1.37];

figure(5)
plot(EFF_SATECHI_4(:,1), (EFF_SATECHI_4(:,3).*EFF_SATECHI_4(:,4))./(EFF_SATECHI_4(:,1).*EFF_SATECHI_4(:,2)).*100, '-o', 'color', [61/255 60/255 56/255], 'LineWidth', 2);
hold on;
plot(EFF_ANKER(:,1), (EFF_ANKER(:,3).*EFF_ANKER(:,4))./(EFF_ANKER(:,1).*EFF_ANKER(:,2)).*100, '-o', 'color',  [227/255 82/255 5/255], 'LineWidth', 2);
hold off;
grid on;
set(gca,'fontsize',20);
xlabel("Input voltage, V");
ylabel("Efficiency, %");

h = text (20, 81,  "Anker Power Drive 2\nP_{out}=6.64W");
set (h, "fontsize", 20);
set (h, "color", [227/255 82/255 5/255]);

h = text (16.5, 78,  "Satechi 72W USB-C PD\nP_{out}=2.90W");
set (h, "fontsize", 20);

title ('Efficiency for USB-A ports')
print('satechi_anker_efficiency.png', '-dpng', '-S1000,500');

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Anders R.
Anders R.
4 months ago

Well written article. It was an interesting read. You need a power supply with more than 5 A of output current.