24 Volt LED strips are increasingly replacing 12 Volt ones. Many have experienced their benefits with both single-color and RGB LED strips. The most important advantage is that with the same cross-section, double the power can be transmitted, allowing for generally half the number of connection points during installation. This facilitates the installation process, meaning that noticeable luminous flux reduction occurs further from the connection points. Many manufacturers already offer 10-meter rolls instead of the usual 5-meter rolls for 24 Volt versions.
Of course, this is not always true, as the power per meter and the construction of the strip also affect this.
A reasonable question arises: what about CCT, or color temperature-adjustable LED strips? Is it enough to connect these 10-meter sections at both ends?
We will also examine how to interpret the nominal consumption of LED strips, as when a controller mixes colors, or in this case the color temperature, manufacturers consider that during mixing, fluctuations in luminous flux are eliminated. Thus, it can be assumed that a mixed color or color temperature will not light up with twice the power as if only one color channel were used. Therefore, we cannot assume that using a multi-color LED strip through a controller will reach nominal consumption.
Currently, the 24 Volt CCT LED strip is also available in 5-meter rolls, so let’s examine it this way first!
This strip has a nominal consumption of 12 Watts per meter, which means 60 Watts for the entire roll. It can be used without a LED strip controller. For example, using a traditional chandelier switch, one circuit can switch on the warm white, and the other can switch on the cool white. This way, we can light up with 3 different color temperatures using the two chip color temperatures: 3000 Kelvin warm white, 6500 Kelvin cool white, and if both are switched on, 4250 Kelvin neutral white. Obviously, we won’t be able to dim the light, but with this solution, we can actually choose between two light intensities, as turning on both color temperatures will nearly double our luminous flux, as well as the consumption.
Although it’s not visible in the table, I conducted other measurements as well. These are less important but somewhat interesting. When lighting with only warm white, the consumption is slightly higher (max. +2 Watts) than when lighting with cool white. On the other hand, lighting with only warm white results in slightly weaker luminous flux compared to lighting with only cool white. This is not surprising, as cool white LEDs have always been slightly more efficient than warm white ones. This was also true 15 years ago in the DIP LED world. The better efficiency is likely due to the phosphor mix that provides the stronger blue light beam in cool white.
The main point is that the consumption exceeds the nominal value when used without a controller, as consumption will exceed 60 Watts when both color channels are turned on. Moreover, this is true even if the strip is connected from only one end. When connected from both ends, consumption exceeds the nominal value by 25%, which is quite significant. Therefore, anyone considering such controller-less operation must ensure the installation of a power supply stronger than the nominal consumption and also account for greater heat generation than planned.
When operating the LED strip through a CCT LED strip controller (which is actually the expected normal operating mode), you can see that if you turn on both color channels – in reality, setting the controller to neutral white – the controller mixes the two color channels so that the luminous flux and consumption behave as if only one color channel were operating. In the table, I did not include the parameters for 1-color channel operation with a controller, as it is the same as if we were not using a controller.
From the table, for any lighting mode, you can see how “grateful” this LED strip is if you also supply power to the far end. In fact, not only the far end but even the middle of the strip (measured at 2.5 meters) will light up more brightly. We can say that when connected from both ends, the far end of the LED strip will light up on average 25% more strongly (not percentage points). That is, if we only connect the strip from one end, the far end will light up 20% less brightly than the beginning. This difference is not noticeable if the strip is installed in a straight line. If you fold the far end back to the beginning, you will see it.
But even at 2.5 meters, that is, in the middle of the strip, you will experience about a 10% weaker light if you only connect one end of the strip.
If you connect both ends of the strip, you will still notice about a 10% light deficit in the middle of the LED strip. Therefore, if you want to install this strip with really precise and even luminous flux, it might be advisable to cut it at 2.5 meters and provide power connections in both directions there as well. However, everyday practice shows that this is overly precise. In reality, connecting both ends of the 5-meter strip results in satisfactorily even illumination. The 10% deficit measurable at 2.5 meters will not be noticeable because the LEDs in both directions will gradually get stronger in groups of 6, so over 2.5 meters, the 10% deficit is spread over 25 fine steps, and there is no installation situation where two very different strength LED sections come close to each other.
| 5-meter Pannon CCT LED strip, nominal 60W consumption, 24V |
Consumption without power supply, Watt* | Relative illumination values** | |||
| At 0 meters | At 2.5 meters | At 5 meters | |||
| Direct connection from 1 end | 1-color | 34 | 51% | 44% | 41% |
| Direct connection from 1 end | 2-color | 64 | 99% | 81% | 77% |
| Direct connection from 2 ends | 1-color | 39 | 52% | 49% | 52% |
| Direct connection from 2 ends | 2-color | 75 | 100% | 90% | 100% |
| With Miboxer controller from 1 end | 2-color | 35 | 51% | 42% | 41% |
| With Miboxer controller from 2 ends | 2-color | 39 | 53% | 47% | 53% |
* The consumption measurement was conducted together with an 87% efficiency 150 Watt throughput 24 Volt LED strip. Therefore, the measured value without the power supply takes into account 87% of the measured value.
** The measurement was actually an illumination measurement, not a luminous flux measurement. I measured the lux values of 10cm long LED strip sections through a 1 meter long and 10cm diameter tube. These measured lux values have no practical significance as absolute values. The key here is comparability. So I took the strongest measured value as 100% and proportioned the other values accordingly. Although these ratios originate from illumination values, since the same LEDs have the same lighting angle, they logically result in valid ratios for luminous flux as well.
Let’s examine the feasibility of a design that considers the possibility of installing a continuous 10-meter strip.
This is because our online store also offers RGB and single-color 24 Volt LED strips in original 10-meter factory reels.
In the case of connection without a controller, we encounter the same situation as with the 5-meter reel, with the difference that while with the 5-meter reel the performance increase when using both color channels compared to one color is 88-97%, i.e., consumption practically doubles, this ratio slightly moderates to 68-86% with the 10-meter reel.
Why is this? Well, let’s see. In the single-end connection, the luminous flux at the far end is 49-57% less than at the connection point. In the two-end connection, the situation is understandably better, as the luminous flux deficit is 21-23% at the middle of the strip, at 5 meters. This is logically twice as much as the 10-12% deficit experienced at the middle of the strip in the above table with both ends connected.
If we examine these parameters in a logically expected CCT-controlled connection, we find that even with a single-end power supply, the luminous flux at the far end of the 10 meters is halved compared to the connection point. If we connect both ends of the 10 meters, the luminous flux deficit in the middle is 18%, which is only negligibly better than without a controller.
| 10-meter Pannon CCT LED strip, nominal 120W consumption, 24V |
Consumption without power supply, Watt* |
Relative illumination values** | |||||
| At 0 meters | At 2.5 meters | At 5 meters | At 7.5 meters | At 10 meters | |||
| Direct connection from 1 end | 1-color | 50 | 49% | 38% | 31% | 25% | 25% |
| Direct connection from 1 end | 2-color | 84 | 92% | 67% | 52% | 41% | 39% |
| Direct connection from 2 ends | 1-color | 67 | 51% | 41% | 40% | 41% | 51% |
| Direct connection from 2 ends | 2-color | 125 | 94% | 76% | 72% | 76% | 94% |
| With Miboxer controller from 1 end | 2-color | 50 | 50% | 38% | 32% | 26% | 25% |
| With Miboxer controller from 2 ends | 2-color | 68 | 50% | 42% | 41% | 42% | 50% |
* The explanation is the same as in the table above.
** The explanation here is also the same as in the table above, with the note that for easier understanding, the 100% value is not in this table but in the one above presenting the 5-meter strip. The results of the other measurements are relative to the 100% value measured there.
Overall, we can conclude the following:
- This is a high-performance and well-constructed LED strip. Do not install it carelessly!
If the manufacturer still offers it in 5-meter rolls despite being 24 Volts, there is a reason for that. - The reason is evident from the above. If we connect both ends of a 5-meter roll and use a CCT controller, then in the middle – at 2.5 meters – the light flux drop is not even noticeable to the eye, with only a 10% reduction.
- If we try to save on such construction, we will only experience worse lighting.
- If we decide to install such a valuable LED strip, we should not try to save on the installation method. Choosing a momentarily easier and cheaper installation method will make us endure its disadvantages for years. Moreover, due to poor installation, the LED strip, acting as a resistor, heats up the LEDs and shortens their expected lifespan.
- Using a CCT-LED strip controller not only provides the convenience of remote control but also allows us to adjust the brightness. More importantly, we bought the CCT LED strip to adjust the color temperature to our needs and lifestyle. It is entirely natural and logical to expect a controller to strive for the same light flux regardless of the color or color temperature set. No one should be surprised that a LED strip will not have double the light output at neutral white color temperature when operated through a controller.
- Another possibility, which will spread with the rise of smart systems, is that if a controller is Wi-Fi enabled or part of some smart system, we can set it through our mobile application to light up with the appropriate color temperature at any time of the day, or according to our circadian rhythm if it differs from the standard. Many may consider this unnecessary until they face some sleeping or falling asleep problems.