Kaiweets Voltage Tester Pen Review (VT500)

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There are several tools you can use to check the voltage on electrical circuits. You can use a multimeter, socket tester, clamp meter, or the traditional screwdriver tester among other tools. But the easiest of them all that is easy and safe to use is a non-contact voltage tester.

A non-contact voltage tester pen, also known as a voltage detector pen or contactless circuit tester, is a small handy tool that checks the presence of voltage in a circuit without making any physical contact with the circuit system. It uses a sensor to detect the electromagnetic fields generated by electrical currents.

The advantage of using a non-contact voltage tester pen is that it allows you to detect voltage without physically touching the electrical system. This makes it one of the safest tools for testing electrical systems because it eliminates the risk of electrical shock or short-circuit.

There are many types and brands of contactless voltage tester pens in the market. They all work the same but may differ in terms of accuracy and other auxiliary features such as alert methods.

In this article, I explore the Kaiweets VT500 voltage tester. I received it from the manufacturer for testing and thought it would be important to share with you my experience.

Form Factor/Appearance

The Kaiweets VT500 voltage tester shares the same design as other pen-shaped testers. It is 5.7 inches long and feels quite solid. The tester pen includes a convenient shirt clip, making it effortless to transport with you on-the-go.

Key Features

  • Battery cell polarity tester
  • Visual and audible alerts
  • Detects and measures voltage
  • Double as small flat screwdriver

Features & Functions of Kaiweets VT500 Tester

Kaiweets’ VT500 electrical tester pen has several features and functions that make it stand out among other tester pens. They include:

Main Functions

Contact and non-contact voltage detection & measurement

The Kaiweets VT500 is designed to work as an ordinary contact voltage tester pen or as a contactless tester.

Checking wall outlet with Kaiweets VT500 tester pen

It has a metallic tip that makes it possible to touch electrical systems to detect and measure voltage. The LCD screen displays the value of the voltage. If the voltage is high, the screen displays the value and turns red.

If you want to get the most accurate voltage measurements with this tool, place the slotted tip on the circuit system. you can also measure voltage without getting the tool into contact with the voltage source but the value you get is misleading. It is nowhere near accurate.

For instance, it tried to measure 240V voltage in an insulated cable and the maximum the tool could sense without touching the conductor was 12V. This is grossly misleading and can be catastrophic.

As a non touch voltage tester, this VT500 from Kaiweets is only good for sensing voltages but not measuring. It can detect voltage on insulated wires from a distance of 10mm. As you move closer to the source, the frequency of the audible alerts increases.

Battery cell polarity checker

You can use the Kaiweets VT500 to check polarity of battery cells. It detects the positive terminal of the cell.

This feature is not very useful because most battery cells have labels that identify the terminal as (-) or (+). Furthermore, battery terminals have different shapes.

But if you want to confirm that a battery cell is properly constructed and labeled, you can use this tool. Just put the screwdriver tip on one side of the cell and your finger on the other. The tester will beep if the tip is touching the positive terminal.

This battery polarity check feature is just for fun, IMO. I don’t find it useful at all because battery terminals are usually well-labeled. But if you are trying to be a magician, you can use this feature to trick your audience. I am sure many will fall for the trick but not me 😜.

Screwdriver function

Most non-contact electrical testers have plastic tips but the VT500 has a metallic slotted screwdriver tip. You can use it as regular screwdriver to remove or install small screws on wall outlets and light switches. The screwdriver tip is however not strong or wide enough for large screws.

Also, do not apply too much torque to tighten or undo a screw because you might damage it. So, if a screw is too tight, just use a screwdriver to avoid damaging this tool. Remember the metal tip is your sensor, you must protect it for your tool to work properly.

Key Features


Accuracy is what separates chaff from the grain when selecting the best voltage tester. An inaccurate voltage detector is not only misleading but can expose you to dangerous electric shock.

The Kaiweets VT500 is fairly accurate at detecting the presence of electric current in cables and wiring circuits. It will produce beeping alerts that will increase in frequency the closer you get to the live wire or circuit.

However, this tool is not accurate at measuring voltages without contact with the conductor. So don’t rely on the non-contact voltage readings you get from it.

But the reading you get from the tool when the tip comes into contact with a live conductor is fairly accurate. For example, without contact, the tool was only able to detect 12V from a wall socket while with contact, it was able to read 230V.

So, the general rule of thumb is that, when using the VT500 voltage tester pen to measure voltage, bring it into contact with the conductor. Otherwise, the contactless feature will be fine for detecting the presence of voltage in a circuit or wire.

Alert mechanism

The VT500 electric tester pen is loaded with multiple alert mechanisms. It beeps whenever it detects a voltage signal and the frequency of the beeps increase the closer you get to the source.

Furthermore, the LCD screen displays U for low voltages and “Hi” for high voltages. It also lights up red at high voltages.

Kaiweets VT500 Voltage Tester Review [Video]

This is a video review of Kaiweets VT500 non-contact voltage tester. A voltage tester pen is an essential device for electricians, DIY enthusiasts, and anyone who needs to safely test the presence of voltage in electrical wires, sockets, or light switches.


Overall, the Kaiweets VT500 voltage tester pen is good value for money. It is a nice pocket tester to have on hand for checking voltages to ensure safety when working on electrical wiring circuits. You can use it to detect and measure voltages on light switches, junction boxes, fuse boxes, and wall outlets.

This compact tester is easy to carry around in the pocket and even doubles as a small screwdriver. But one downside is that it lacks a protective cap for the screwdriver tip, which can potentially scratch your skin through your clothing or puncture your pocket. To avoid this, always fit the small plastic sleeve on the tip or screw on a wire nut lightly. Taking this precaution will help safeguard both yourself and the tip of the tester.

protecting vt500 tip with a wire nut
Protecting VT500 screwdriver tip with a wire nut (Source: Amazon)

Hey there! I am an field electrical engineer by day, a blogger by night, and DIYer on weekends. Throughout my career, I have used many tools and learned that getting the right tool for the job is the first step to getting the job done right. This is why I write about tools and tests/reviews them on this blog.

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