LED Strip Lights: Performance And Reasons Of LED Voltage Drop

The LED voltage drop will affect the use and installation of the LED light strips, understanding the voltage drop can answer some of the problems you encounter.

What we will talk about next:

  1. What Is Voltage Drop? Why Does The LED Voltage Drop Occur?
  2. Do all LED strip lights have a voltage drop?
  3. How To Find Voltage Drop?
  4. What Factors Will Affect The Voltage Drop?
  5. How To Avoid Voltage Drop?
  1. What Is Voltage Drop? Why Does The LED Voltage Drop Occur?

Running a 5m/16.4ft led strip, the voltage of the fifth meter is significantly lower than the voltage of the first meter, and we call this led light strip a voltage drop. The electronic components on the led strip light consume voltage too. On LED lights, the brightness is often reduced, the led strip is dimmed, and the light color changes. They are all performance of the led voltage drop.

At the same power, the voltage drops and the current rises. And if the current is too large, the led lighting strip will be damaged by heat.

Power = Voltage X Current.

For example, we power a 75W 12V 5m led strip light, the voltage of the first meter is 12V, and the current is 6.25A. Running to the fifth meter, the voltage may drop to 10V, and the current is 7.5A at this time. So, the appearance of the voltage drop is accompanied by the heating of the light strip, and the overheating is a fatal danger. Therefore, in order to prolong the service life of the LED lights strip, we must pay attention to the problem of the voltage drop.

  • The first meter: 75W ÷ 12V = 6.25A
  • The fifth meter: 75W ÷ 12V = 7.5A

The voltage drop does not only exist in the led light strip, if the connection wire between the led transformer and the strip light is too long, it will also cause a voltage drop. Don’t worry, we will talk about it below.

1.1 Do all LED strip lights have a voltage drop?

Due to the design principle of constant voltage led strip lights, 5V led strips, 12V led strips, and 24V led strips will inevitably have voltage drops during long-distance operation.

High voltage led strip lights use AC high voltage electricity with strong energy. Compared with low voltage led strip lights in the same running length like 10m, at the fifth meter, the current flowing through is smaller and the voltage is more sufficient, so high voltage led strips can run for a distance of 50 meters without voltage drop.

When it comes to constant voltage, it is hard not to think of constant current. Due to the rated current of the constant current led strip light, a more constant current IC in the strip, the voltage will not fluctuate greatly during the led strip operation, thus ensuring brightness consistency. Constant current led strip lights are also one of the options for long-distance running.

  1. How To Find Voltage Drop?

The LED voltage drop is most obvious on the white led strip, so on the color changing led light strip, you can turn on the white light to see the voltage drop.

Let’s run a long white light led strip to see if it will show a voltage drop. In the below picture, we can see that the beginning (position “1”) is clear white, and after running for a distance (position “2”), the white light gradually turns yellow, and at the end of the led strip (position “3”), the white light turns red due to the decrease in voltage.
(Reminder: When the led light strip is rolled, it should not be lit for a long time, which will damage the led strip.)

LED strip voltage is related to LED color. Below are the voltages required for several color drives.

  • White LED: 3.0-3.3V
  • Yellow LED: 1.8-2.0V
  • Red LED: 1.8-2.2V

The driving voltage of the white LED is greater than that of the yellow LED and the red LED, so when the voltage of the white led strip light drops and the current voltage cannot meet the voltage required by the white light, the light strip will display yellow and red because they are lower than the voltage required by the white light.

  1. What Factors Will Affect The Voltage Drop?
  • Voltage: The higher the voltage, the lower the voltage drop. DC24V led strip lights obviously have less voltage drop than DC5V led strips.
  • Current: The thicker the PCB, the more current allowed to flow through the circuit, 2 oz copper is a good choice.
  • Running length: The large voltage drop of the led strip lighting means that the actual safe running distance is short. Considering only the running length, high voltage led light strips and constant current led strips are more suitable for your project than low voltage led strips. If you just want a low voltage led strip light, 24V runs longer than 12V.
  • Wire gauge: If there is no power supply near the installation location of the low voltage led light strip, you can only extend the connecting wire and place the power supply at a distance from the strip, then you need to choose the appropriate wire gauge for your extension cord. Find the wattage of your strip in the wire gauge table below, and how long the power supply from your led strip, combining the two will give you an idea of what wire gauge you need to extend your strip.

For example, my 60W 12V led strip is 2.7m/9ft far away from my led driver, I should choose the 16AWG wire cable to prevent the voltage drop.

12V voltage drop chart
24V voltage drop chart
  1. How To Avoid Voltage Drop?

1) Use higher voltage. LED Voltage Drop: 5V led strip > 12V led strip > 24V led strip.

2) Use constant current led strip lights.

3) Connect the led strips in parallel.

4) Power supply at both ends of the led strip light.

About how to wire low voltage led strip lights, we have articles mentioned in detail: