Device not charging? Is it the cable? Is it the Charger? Is it the device? How can you make sure, without wasting money?



You can easily do this with this inexpensive Electronic Load. I got it from Amazon, for NZ$33.62.



What's its specifications?


Voltage Range: DC 3.5V-21V
Current Range: 0-3A continuously adjustable (rough adjustment steps: 0.2A, precise adjustment steps: 0.02A)
Power Range: 0-35W
Voltage Deviation: 0.01V
Detector of Smart Temperature Control: NTC thermistor [On the MCU]
Important Note:There is no actual Temperature control or Temperature protection on the Load Resistor, or Load MOSFET. Which can cause small inaccuracies in very long tests, and cause fires.

Switching Regulator IC Frequency for Fan: 1.2MHZ
Fan Speed: 2900RPM, 40x40x20mm(1.58*1.58*0.79 inch)
Radiator: 6063 aerospace aluminum radiator, 40x40x10mm(1.58*1.58*0.4 inch)
Operating Temperature: -10°C ~ +65°C (14°F-149°F)
Product Dimensions: 100x48x30mm(3.94*1.89*1.81 inch)

Connectors


This product comes with two full size USB connectors, allowing you to both simulate a load, and to see how much current a device is pulling through the connector.No alternate text provided
Not only that, it also comes with a plethora of connectors, one Mini-USB, two Micro-USB (One only provides power to the MCU, not the load), one Lightning, one USB Type-C, and one bare-wire terminal.
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These allow you to test the Charger, the cable, and even the end device!

Product Quality


The production quality is alright. The Acrylic base wasn't attached correctly. And there is a lot of grunge left on the PCB from the Hand Soldering.
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But all the ports are there, and everything is properly soldered, and after 5 seconds with a screwdriver everything was actually held together by two screws, so it's not that bad.

Although after a few weeks, the Screen's Double sided tape detached from the side of the fan, a small bit of sanding the plastic on the side of the fan, and a little dab of super glue fixed that problem.

Usage


First you want to connect a Micro-USB cable from a stable 5v Power source to the "SYS_PWR" connector (It's the closest Micro-USB port to the Full Size USB port), otherwise if the voltage or current from the load drops below 3.5v or 100mA, the Microprocessor will brown out and reset everything, and the screen will be illegible. Once it starts up you are presented with this screen:
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The first screen is probably the only screen you ever need to see, it contains:

After pressing the single button, you get to the second screen:
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Which contains:

After pressing the single button, you get to the last screen:
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Which contains random parts from the previous two screens.

You can press the same button to loop back to the first one, or press and hold the button for it to reset the counts, and accumulated values.

Accuracy


I tested it both using a Multimeter and USB Power meter, and both were within 1% of the value shown on this device.

While it's not accurate enough to be used in scientific tests (Admittedly you would never use something like this, since it has no Data Logging capabilities), but it's easily accurate enough to be used to eyeball whether or not a power source is providing its rated power.
If I had to give this an subjective score I would give it a 10 of 10.
Aside from some minor finish issues, it works perfectly. It would have been nice to have a thermistor on the load MOSFET, to control any temperature issues.
You can get a uniquegoods 35W Electronic Load from:
Amazon: