LED strip light PCB is made of copper. As we know, copper has electrical resistivity. That means when we use the PCB longer, then the voltage will be less in the end than in the beginning. We should think about how to avoid the voltage drop.
Many customers will have the question, How long can we use the led strip light? How is the voltage drop at the end of 5 meters led strip light? Does DC24V voltage better than DC12V? How long can I connect the led strip light? How long can I use the electrical cable from the driver to the led strip light?
In this post, we will make a test.
1, DC12V Led strip light voltage drop test
2, DC24V Led strip light voltage drop test
3, Long cable with led strip light voltage drop test
1. What’s a Voltage Drop?
From Wikipedia, we know voltage drop is the decrease of electrical potential along the path of a current flowing in an electrical circuit.
When we use LED strip lights, the longer led strip light we use, the longer cable we use, the more voltage drops happen.
When voltage drop happens, the beginning of the strip light will be brighter than the end of the strip light.
2, DC12V Led strip light voltage drop test
1,In the beginning of the led strip light .The Voltage is 12.54V
2,In the end of 5 meter of the led strip light .The Voltage is 11.5V
3,In the end of 10 meter of the led strip light .The Voltage is 9.92V
4,In the end of 15 meter of the led strip light .The Voltage is8.9V
5,15 meter DC12V led strip light test
3,DC24V Led strip light voltage drop test
1,In the beginning of the led strip light .The Voltage is 23.8V
2,In the end of 5 meter of the led strip light .The Voltage is 21.7V
3,In the end of 10 meter of the led strip light .The Voltage is 18.8V
4,In the end of 15 meter of the led strip light .The Voltage is 17V
5,15 meter DC24V led strip light voltage drop test
|12V Voltage Drop Test|
|3led/unit (every led voltage)|
|24V Voltage Drop Test|
|6led/unit (every led voltage)|
From the test report, we know DC12V and DC24V, the voltage percentage in the same length is almost the same. But we can see, the DC12V led strip light is 3 led/unit, and DC24V led strip light is 6led/unit. Then means the same voltage drop, DC24V voltage drop for every LED is only half the percentage voltage drop of DC12V. So if you use longer led strip light, we suggest using DC24v led strip light.
4,Long cable with led strip light voltage drop test
1,10 meter cable and 15 meter DC24V led strip light voltage drop test
2,In the beginning of the cable .The Voltage is 24.2V
3,In the 10 meter end of the cable .The Voltage is 24.3V ( Thick cable is ok.)
4, connect 10 meter (2pcs *5meter) LT- 5050WW60R-W24.In the beginning of the strip , the voltage is 17.9V
5,In the end of the 5 meter strip light ( 10 meter cable+5 meter strip light). The voltage is 17.1V
6,In the end of the 10 meter strip light ( 10 meter cable+10 meter strip light). The voltage is 16.8V
7,In the end of the 10 meter strip light ( 10 meter cable+15 meter strip light). The voltage is 16.2V
5. How Does a Voltage Drop Happen?
There are some factors that caused voltage drop: Input voltage, wire gauge, length of the wire, strip light wattage.
Voltage input (DC12V or DC24V)
The higher the input voltage, the smaller the voltage drop. For the same length of the strip light, each led lamp, DC12V strips will lose voltage more than DC24V led strips.
The larger size of the wire, the smaller the voltage drop. For example, 20 meter AWG20 wires, The voltage drop 1 voltage. 40 meter AWG16, the voltage drop 1 voltage.
The same size of the wire, the longer the wire, the greater the voltage drop. That is easy to understand. 20-meter wire voltage bigger than 10-meter wire.
Amount of wattage
The total wattage of the led strip light will affect voltage drop levels. If the wattage increase, the current will increase in the wire. Then voltage drop will bigger.
6. How to Avoid Voltage Drop?
Voltage drop is a problem for led strips. We can follow some tips to avoid voltage drop.
If you want to install 30 meters led strip light around the ceiling, you can use the parallel connection to avoid voltage dorp.You can use 2 ways to connect the led strips as follows:
a: 5 meters each connect to the power supply:
b: 10 meters each connect to the power from both sides:
Please note, for different wattage of led strip lights, the recommended max running length could be different, take our 2835 strip light for example:
|Item No.||Power||Max length
(Power from one side)
(Power from both sides)
Use 24 Volt driver
If you are install led strip light for a large lighting project, the best way is to use a DC24V led strip light. It will less voltage drop than DC12V led strip lights.
Multiple power drivers
For some projects, we can use multiple power suppliers. This will easy wiring, and the brightness will not different. And small drivers don’t have fans. It is quiet for home use.
Use an LED strip with thick copper PCB
We use copper as the PCB material. This is because it conducts electricity much better. The thickness of copper PCB is usually rated in ounces. The thicker the copper PCB, the more current can flow through. We recommend using 2 ounces, or 3 ounces for higher power LED strips to avoid voltage drop.
The thicker the copper PCB, the less the internal resistance. As such, the copper PCB will carry power more efficiently. In addition, It’s more conducive to heat dissipation.
Identify Correct Wire Gauge
If you need long wires, always select the thick copper one to avoid voltage losses.
Follow the tips to select the right wire gauge
Step 1. Calculate the wattage of the strip light
Calculate the total wattage of your led strips.
For example, if you need 5 meter LT-2835WW60R-W24, the total wattage is 9.6w*5mtr=48w.
Step 2. Calculate the distance between strip lights and power supply
Now, you need to measure the distance between your power supply and the LED strips. This will help you select the right gauge.
Step 3. Select the right gauge
From above, you know the requirements, you can select the right gauge from the chart.
12V Voltage Drop & Wire Length Distance Chart
24V Voltage Drop & Wire Length Distance Chart
Voltage drop is not an unsolvable problems.We need to know how the voltage drop happen and how to avoid the voltage dorp.Then we can use our led strip light,and the led strip light brightness in a very good condition.
Founder of Lightstec.Engineering degree.More than 13 years working experience in led lighting business.Familiar with producing led lighting products.This blog share you knowledge and solution in led lighting.Welcome sourcing led lights from China.
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