There’s nothing more aggravating than having a full battery in the morning only to find it completely drained when you really need it. I don’t have time to play the guessing game of how much power my USB is drawing.

The DROK USB 2.0 is a power savior. The model allows you to test USB port problems and the charging capability of old or third party chargers and outlets. The meter monitors output differences of any USB port. You can see the drop in voltage as the device reads your supply while charging the current. Sorting sub-par cables and chargers from the useless ones becomes easier to power through.



DROK makes life a bit easier. With a lightweight design of 2.4 ounces and dimensions 2.7’’ x 1’’’ x 0.6’’, the DROK 2.0 is easily portable, compact, and versatile. The unit consists of two outputs. Output I offers the dual function of charging and data transfer. The second output is a built-in smart charging control IC that automatically matches the safest and correct currents for your devices. Seven testing modes provide information on capacitance, power, voltage, and amps.

This universal meter is perfect for either original or non-original chargers (like solar), mobile phones, tablet PCS and other USB devices like BC1.2 yt/d1591-2009 and non-BC1.2 gadgets including iPad, iPhone, and the Samsung Galaxy.

DROK’s charging current is determined by compatibility. Plus, you can view the voltage and current values at the same time. The power draw is less than 10mA and doesn’t significantly load test devices or PSU. Although voltage and amperage readings are on other devices, the power and MAh draw are bonus touches.

Another positive is that you can easily determine voltage drop of some new and “heavy duty” USB cables. I swapped separate cables between a fixed charger, the Drok, and a battery being charged and simply read the meter. I was pleased to see the larger AWG wire I used for USB power leads in the new cables improved charging current.

The pro of the display is the clear, dual-LED screen so it’s easy to see indoors. It’s fun to charge your phone to 100% while learning how settings like screen brightness affect power.


But there are also some minor cons. What doesn’t make it accessible are the instructions. The manual isn’t straightforward and only tells you what the display shows. Also, keep in mind that “capacitance” mean watt-hours transferred.

Display-wise it’s hard to see in bright sunlight, which is a pain if you’re testing solar panels. It also doesn’t shut off which is a pro for some and a con for others because the display takes a small amount of charging current (<20mA) to power. Personally, this is a minor flaw and doesn’t necessarily negate the usefulness of the device.


With almost everything charging from USB ports today, this device can be a useful tool. DROK is significantly less expensive than competitors like the PortPilot so it’s an economical purchase.

It will increase your devices’ lifespans and notify you when to get better chargers. This meter is a great way to monitor your relationship with your electronics. For the price, it’s reliable and multi-purpose. So, DROK and roll.

Praveen Kailas

About Praveen Kailas

Praveen Kailas is a lifelong A/V and modern electronics enthusiast. His A/V experience is primarily on the user side, and this experience comes not only from Praveen's personal endeavors, but also from his professional work in the fields of home construction, energy efficiency projects, and home automation. His personal website can be found at http://praveen-kailas.com.