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Plugable USB-C Voltage and Amperage Meter


  • Allows quick and easy monitoring of USB-C charging. Measures voltage and amperage as well as what direction electrical current is flowing through it.
  • Features bright and easy to read OLED screen
  • Meter is bidirectional and can be connected in any direction.
  • Supports the full range of USB-C Power Delivery voltage from 5 to 20V (4-20V, 50mA-10A operating range)
  • The meter passes through all USB data (1.1 through 3.1 Gen 2), USB-C Alternate Mode video, and USB-C charging without interfering with normal USB-C operation.
  • Can be used inline with USB-C docking stations, chargers, USB-C accessories, etc
  • The compact aluminum design makes this the perfect companion for diagnosing and monitoring USB-C devices on the go with no extra equipment required

Note: If purchased after Q1 2018 we have an updated version of our USBC-VAMETER:

This new design now features a molded plastic shell which enabled us to make the meter thinner and fit most phones while inside of a case. We also added the ability for the meter to calculate approximate mAh charged during the charging session with the meter connected. Aside from these minor changes the VAMETER functionality is identical.

Units purchased prior to Q1 2018 look like this:

Product Description

The Plugable USBC-VAMETER is a portable USB-C multi-meter that was designed to measure voltage and amperage (charge rate) for USB-C devices.

Plugable is already well known for our advanced USBC-TKEY USB-C Power Delivery Analyzer based on Google’s open source “Twinkie” design, but for many users it provides far more functionality than required and is more complex to setup (requiring a Linux computer). For most users a simple stand-alone, plug and play, on-the-go solution is required and the USBC-VAMETER is the perfect solution with its ability to display USB-C voltage, amperage, and current flow direction in real time.

Common use scenarios would include the following:

  • Connecting between a USB-C host system like a laptop, tablet, or cell phone and a charger to monitor charge information.
  • Connecting between a USB-C host and docking station to monitor charge information.
  • Connecting between a USB-C host system and a USB-C bus powered accessory like an external hard drive, flash drive, etc to measure power draw of a device.
  • Testing for USB-C port spec compliance such as a VBUS hot condition, voltage drop under load, etc.


We designed this meter to act as a transparent interposer which means it should not interfere with the USB data (1.1 through 3.1 Gen 2), USB-C Alternate Mode video, or USB-C charging. Can be used inline with USB-C docking stations, chargers, USB-C accessories. The meter is able to achieve this without interfering with normal USB-C operation as it only taps into the power (VBUS) and ground connections to measure their values and leaves all of the data lines untouched.


Q: What does the arrow flashing on the screen stand for? What about a straight line?
A: The arrow will change direction pointing in which direction the current is flowing. If you see a straight line it means there is not enough current flowing in either direction to meter.

Q: How accurate are the voltage and amperage measurements from this meter?
A: In our testing we’ve found that compared to a professional multimeter, our USBC-VAMETER is within +/- 3% of the true value (measured at 20V). This meter is not meant to replace professional USB-C testing equipment, it is designed for quick and easy measurements for users at any skill level.

Q: How to I calculate the wattage from the provided voltage and amperage information?
A: Users can calculate how much power a device using this simple formula: The power P in watts (W) is equal to the voltage V in volts (V) times the current I in amps (A), P = V × I.

In The Box


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