Many LED strip users mistakenly believe that low-voltage LED strips can be used in 50-meter or 100-meter rolls. While IP20 strips can be made in 50-meter rolls, they cannot be used together due to voltage drop. A key technical question often arises: how long maximum length can an entire LED strip lights actually be connected? Many people mistakenly believe it can be infinitely spliced until they notice the light at the end dims significantly. The color is distorted, or it doesn’t light up at all. The core of this problem is not the quality of the strip itself, but rather stems from a fundamental physical principle—voltage drop.
The following will guide you through a clear and concise explanation of the causes of voltage drop in LED strips, systematically analyze all factors affecting the maximum length. And provide a complete solution from calculation and extension to purchasing.
Why Can’t LED Light Strips Be Connected Indefinitely?
When an LED light strip is lit, as current flows from the power source through the strip, some electrical energy is converted into heat due to resistance. This causes the voltage to decrease as the transmission distance increases gradually.
This means that the LED chip at the beginning of the strip receives a standard voltage (such as 12V or 24V), while the chip at the end receives a lower voltage.
LED chips are very sensitive to voltage. Insufficient voltage directly results in decreased brightness (light decay), yellowing (for white light), or color shift (for RGB light strips). In severe cases, it can even affect the lifespan of the LED tape.
What Factors Affect the Maximum Length of an LED Light Strip?
The maximum continuous power supply length of an LED light strip is essentially determined by the “minimum threshold at which the voltage can maintain normal operation of the LED at the very end.” Whether the voltage will decay rapidly (i.e., the voltage drop problem) can be analyzed from the following six core technical parameters.
Operating Voltage
Voltage is the primary factor affecting the maximum length of LED light strips. In fact, under the same power conditions, higher voltage results in lower current, less line loss, and a smaller voltage drop.
The most common low-voltage LED light strips are 12V, 24V, and 48V. 12V has a high current draw and a significant voltage drop, resulting in a shorter single-ended power supply length. 24V light strips have lower current draw and a smaller voltage drop, allowing for longer distances.
Under the same brightness and power conditions, the maximum permissible length of a 24V light strip is typically more than twice that of a 12V light strip. Therefore, 12V can be used for short-distance household lighting. While 24V or 48V must be prioritized for commercial projects, light troughs, and ultra-long linear lighting.
LED Strip Power (W/m)
Based on the core formula for voltage drop calculation: U = I × R, under a constant voltage, the higher the power, the higher the current, and the more severe the voltage drop.
For standard power LED strips (12W-14.4W per meter), we recommend a maximum single-ended power supply of 5 meters. For strips with power exceeding 20W/m, we definitely recommend dual-ended power supply, with a maximum of 10 meters per power source.
LED Chip Density
Both the LED chip type and density have an impact. For example, 60 LEDs per meter results in a lower current load. While 240 LEDs per meter results in an extremely high current load.
Choose LED strips based on your needs. Of course, high-density and large-size LED strips have a dramatically increased current per unit area. Leading to an exponential increase in voltage drop.
FPCB Copper Foil Thickness
The thickness of the PCB board for LED strips is one of the key indicators for judging the quality and length potential of the strip. We all know that the thicker the copper. The lower the resistance, resulting in a smaller voltage drop and allowing for a longer strip.
We typically use 2oz or 3oz thick boards. If a thinner board is used for LED strips, the ends will be severely darkened. And the copper foil lines will overheat.
Power Supply Power and Quality
In many projects, voltage drops are not due to the LED strip itself, but rather to distorted voltage output caused by the power supply operating at the edge of the load. The total power of the power supply we choose must be greater than that of the connected LED strip, and should have ample headroom.
A 200W LED strip should be paired with a 230-250W power supply. To ensure long-term and sufficient power for the LED strip’s operation. We also recommend using multiple power injection points simultaneously.
Installation Ambient Temperature
Installed LED strips require ventilation and heat dissipation assistance, especially high-power LED strips. This is because the resistance of copper increases with temperature, which accelerates light decay in LED strips.
Therefore, we recommend that high-power LED strips be used with LED aluminum profiles for heat dissipation. And installed in well-ventilated locations.
How to Calculate the Theoretical Maximum Connection Length of Your LED Strip?
Before planning your LED strip light project. You need to calculate the power per meter to roughly estimate your power supply requirements. More details, pls read Description des circuits en série et en parallèle des bandes LED
We assume the LED strip is 24V, and the power adapter has a rated output voltage (e.g., 24V DC).
LED strip power per meter (find it on the product specification sheet or label)
Calculation formula: Maximum connection length ≈ (Total power supply × 0.8) / Power per meter
Example: You have a 120W 24V power supply, and the strip is 10W per meter.
Maximum length ≈ (120 × 0.8) / 10 ≈ 96 / 10 ≈ 9.6 meters
(Note: Multiplying by 0.8 is to give the power supply a 20% safety margin, extending its lifespan.)
Comparison of maximum lengths for 12V and 24V LED strips
Based on the principle of voltage drop and practical experience, let’s compare conventional low-voltage 12V,24V and high voltage LED strips. Below are general safety length recommendations:
| Tension | safety recommendations maximum length | Description |
| 12V DC LED Strip | 5 – 10m | For low-power (≤7.2W/m) LED strips, a length of up to 10 meters is acceptable; for high-power (≥14.4W/m) LED strips, a length of no more than 5 meters is recommended. |
| 24V DC LED Strip | 10 – 20m | A 24V system is the best choice for balancing cost and performance, and is generally chosen for architectural lighting and indoor lighting. |
| High Voltage（110V/220V AC） | 50 – 100m | Driven by AC power and operating through a rectifier, the voltage drop has a minimal impact and it is mainly used for ultra-long-distance lighting in engineering projects. |
What Happens If LED Strip Lights are Connected Beyond Their Maximum Length?
Most lighting users calculate wattage before installation. If you ignore the maximum length limit and forcibly connect them in series, you will face the following problems:
Significant Brightness Decrease at the End: This is the most obvious phenomenon, easily noticeable to everyone. LED strips will exhibit a “bright head, dark tail” effect, severely impacting aesthetics.
Color Inconsistency: For RGB/RGBIC strips, chips at different locations will exhibit different color variations due to varying voltages, resulting in extremely inconsistent colors.
Flickering and Uncontrollable Signals: For intelligent addressable strips (such as the WS2812B), excessively low voltage can cause the end-stage ICs (integrated circuits) to malfunction, producing garbled characters, flickering, or complete lack of response.
Shortened Lifespan and Risk of Damage: To compensate for the brightness decrease caused by low voltage, the end-stage LED chips may operate under overload conditions under non-standard operating conditions, leading to premature light decay or even damage.
How to Properly Extend the Length of LED Strip Lights?
If the area you need to illuminate exceeds the maximum length of a single strip, be sure to use the following parallel connection method instead of series connection:
- Dual-ended power supply: This is the most efficient and cost-effective solution, and we always recommend that customers connect the power supply from both ends. Connect the positive and negative terminals of the power supply simultaneously from both the beginning and end of the light strip. This can effectively halve the power supply distance and greatly reduce voltage drop.
- Segmented power supply using multiple power sources: Divide the extra-long light strip into several segments, each within its maximum length, and then connect each segment to an independent power source.
- Use higher voltage models: 24V or 48V systems are suitable for long-distance installations. Such as shopping malls, showrooms, or building facade lighting.
- Use signal amplifiers (for addressable light strips): For smart light strips such as the WS2812B. A signal amplifier needs to be added after each segment’s maximum length (usually 5 meters). This amplifies the data signal and also provides fresh power to the next segment of the light strip.
Recommended Connection Maximum Length for Different Types of LED Strip Lights
Standard 2835/5050/3528/COB Monochrome LED Strip (12V): 5-8 meters recommended.
Standard 2835/5050/3528/COB Monochrome LED Strip (24V): 10-15 meters recommended.
RGB/RGBW LED Strip (12V): Due to the higher current draw of four channels, 5 meters is recommended.
RGB/RGBW LED Strip (24V): 10 meters recommended.
Addressable LED Strip (e.g., WS2812B, 5V): Typically, a single strip should not exceed 5 meters, and a signal amplifier and power injection must be used every 5 meters.
Addressable LED Strip (e.g., WS2815, 12V): Thanks to the 12V voltage, a single connection can reach 10 meters, but for long distances, attention should still be paid to the consistency of color brightness at the end.
Conclusion
The maximum length of an LED lights strip is not arbitrarily determined, but rather by a combination of voltage, current, and power. For large-area lighting, it is best to choose 24V and employ methods such as segmented power supply, double-ended connections, or signal amplification to ensure consistent luminous efficacy and reliable safety.
If you are planning a large-scale Bande lumineuse LED project and are unsure how to calculate the power supply and wiring scheme, please nous contacter.
FAQ
You can connect the 15-meter strip in series into three 5-meter sections. Connect the beginning of each of these three sections directly to the same main power supply using an independent wire. This ensures that each section receives sufficient voltage, resulting in uniform brightness.
It’s not recommended. It’s best to connect them in series at 15-meter intervals. Excessive length can cause current overload and shorten the lifespan of the strips. The recommended approach is to connect them in parallel. Meaning each strip is connected to a separate power supply to maintain voltage stability.
COB strip lights typically use 24V voltage. The maximum recommended length is 10-15 meters, depending on power density and wire width. For longer distances, segmented power supply or customized engineering-grade solutions can be used.
Yes. Excessively long connections can lead to uneven brightness at both ends, overheating of the wires, power overload, and even the risk of burnout. Uneven brightness in the light strip also affects visual appeal and product lifespan.
You can visit Neonledstrip.com. We offer a variety of high-performance LED strips in 5V, 12V, 24V, and 48V. And can customize long-distance power solutions for large-scale lighting projects.