Calculating LED Strip Power: Everything You Need to Know

LED light strips are among the most popular LED products in the lighting market, playing an essential role in almost all lighting projects. However, the variety of light strip products and their different power ratings can leave customers wondering about the calculation of the power of these LED strips. In this guide, we will provide a comprehensive introduction to understanding and calculating the power of LED light strips.

What is LED Strip Power?

The power of LED strips typically refers to the power consumption per meter of the strip. It's important to note that this is not the total power for a 5-meter strip, and we will delve into this distinction further.

Theoretical Power Calculation Algorithm

LED strip suppliers often provide power ratings for different types, such as 3528 with 60 lights and 120 lights at 4.8W/m and 9.6W/m, respectively. For example, let's take a 5050 LED strip with 60 lights per meter at DC12V:

1. DC12V, typically 3 lights/group, yielding 20 groups per meter.
2. The rated current of 5050 LED beads is 60mA.
3. Therefore, the power can be calculated as 12V×60mA×20=14.4W/m.

This calculation demonstrates that the theoretical power of a 5050 LED strip with 60 lights/meter at DC12V is 14.4W/m.

Power Variation with the Same Lamp Beads

When comparing quotes from different suppliers for the same type and number of lamp beads, the power is often similar. However, taking a 2835 LED strip with 120 lights/meter as an example, the power varies under different voltages:

1. DC5V: 5V×60mA×120=36W/M
2. DC12V:  12V×60mA×(120/3)=28.8W/M
3. DC24V:  24V×60mA×(120/6)=28.8W/M
4. DC24V (different grouping):  24V×60mA×(120/8)=21.6W/M

This demonstrates that, even with the same lamp beads and quantity, the power can vary based on the voltage.

Rated Power vs. Actual Power

The rated power represents the maximum current used in the LED strip and is not necessarily the actual power. Actual power is often lower in production to ensure long life and stable quality. Excessive power can lead to poor heat dissipation, potentially causing the strip to overheat and burn out.

Customizing LED Strip Power

Under suitable conditions for heat dissipation and without significant voltage drop, the power of LED strips can be adjusted within the rated power. Customization is possible, but it usually comes with minimum order quantity (MOQ) requirements.

Controlling LED Strip Power

The actual power of an LED strip is often lower than the rated power. To control power, the resistance of the strip can be adjusted. Calculating the resistance involves factors such as lamp voltage, bead voltage, bead current, and resistance number.

Variation in Power Between Batches

With the same configuration, the power of LED strips from different batches tends to fluctuate within a stable range, typically within plus or minus 10%. This fluctuation is normal due to variations in the Vf value of the lamp beads and the resistance used.

Advertised Power for 1 Meter

The convention of advertising LED strip power based on 1 meter is widely accepted in the market. It facilitates testing and reporting in an integrating sphere, ensuring accurate data for brightness and power. Advertised power for a 5-meter roll is not a simple multiplication of the 1-meter power due to voltage drop considerations.

Conclusion

Understanding and calculating the power of LED light strips involves considering theoretical calculations, variations in power under different conditions, and the difference between rated and actual power. Manufacturers often advertise the power of LED strips based on 1 meter for standardized testing and consumer comprehension. If you have further questions or need clarification, feel free to reach out to us. With 12 years of experience in LED strip production, we are here to share our expertise with you.