My KCX-017 USB current and voltage tester

Sometimes you will face problem with USB charging such as charging speed slower than normal, unable to charge, or worse still, you encountered a "reverse charging" whereby current is drawn away from the battery of your device instead of charging it.

The problem could be due to faulty charger, faulty USB cable, or faulty USB port of the device to be charged.

In addition, certain 3rd party USB cables are having quality issue with unstable current flow, or only allow low current flow through it.

A USB tester such as the KCX-017 will be handy to diagnose such situations.

This small gadget only cost around RM25, and works well with wall charger, car charger, power bank, etc. by connecting its attached USB cable to the charger, or by connecting the charging cable to its micro-USB port. It will measure the input voltage and display on its LCD screen.

Its other end is a USB port which you can use a USB cable to connect to a charging recipient such as mobile phone, tablet, GPS navigator, etc. Beside the voltage, it will also measure and display the current drawn by the recipient, and also calculate the mAh value of the charging session.

In summary, this gadget is used to:

• Test no-load voltage of the power supply
• Test output power of USB output devices
• Test working voltage and current of the USB output devices
• Test voltage and line loss of charging cables
• Perform real-time monitoring of the charging status

Its specified working environment is as below:

• Voltage range: 3-7V
  
• Current range: 50mA-3,500mA
  
• Capacity range: 0-19,999mAh

When the input voltage is lower than 4.7V or higher than 5.3V, its LCD screen will flash with an arrowhead indicating under-voltage or over-voltage.

This device can record up to 10 sets of readings. There is a button near to its LCD screen.

• Double click the button, the display will start flashing. Single click the button to switch to different memory slot (from 0 to 9). Double click again to use the current memory slot displayed on screen.
• Long press the button will reset the next memory slot reading back to 0000.

This device is able to memorize the last reading when unplugged. The next time when it is turned on again, that reading will be displayed on its LCD screen.

It is a handy device to troubleshoot USB charging problem, as well as to test for the charging quality of USB cables.