What are the Actual Watts of my LEDs in my Red Light Therapy Panel?
As a follow-up to our recent review of the Red Light Therapy Panel from Alibaba, we dive deeper into this light to understand the Watts.
The Watts in the lighting industry refers to the power that is consumed by the light. For example, remember all of those 60W incandescent light bulbs in the past? Eventually those were replaced with "60 Watt equivalent" LEDs or compact florescent bulbs.
We see a 60 Watt incandescent bulb next to it's 60-Watt equivalent LED, which is only 10 Watts.
This type of classification has carried over to the Red Light Therapy market. Often lights will advertise the Watts of the LED panel. This is not to be confused with the intensity which is the power output in mW/cm^2 (milliWatts per centimeter squared). LEDs are not perfectly efficient, so the wattage consumed doesn't tell you much about the actual intensity emitted.
- Watts usually refers to the power consumed.
- Intensity or Irradiance in mW/cm^2 refers to the power density emitted.
Then we see an even more confusing trend in the Red Light Therapy industry. Companies will advertise the "rated wattage" of the LED bulbs, yet the LEDs are almost always run much lower than the rated wattage to reduce heat generation and prolong their usable life.
Now we see a war to make high-powered LED Panels by claiming to jump from 3 Watt LEDs up to 5 Watt LEDs. But where is this new technology coming from, and how does it work?
We can learn more about the LED wattage ratings from this blog on LEDsupply. They try to explain the differences between 1-Watt, 3-Watt, and 5-Watt LEDs!
So we see how this confusion affects the lighting industry the same way there is confusion in the Red Light Panel industry!
Case Study: SAIDI BV301 Red Light Panel
In our last blog we said how impressed we are with the quality of the SAIDI light panel. However, there is a strange discrepancy in their advertised wattage.
Advertised "Rated" Wattage: 300W
Number of LEDs: 60
Individual "rated" LED Wattage: 5 W
So we have a panel featuring high-tech 5 Watt LEDs. We might presume that this panel is going to be very high powered compared to their common 3 Watt competitors.
I emailed my contact at SAIDI, and asked them to tell me actual consumed wattage. I asked them for a picture of the power-supply test to verify it.
Power supply test shows 92.8 Watts being used by the panel.
This is a fairly easy thing to test, any decent company should be able to tell you the actual wattage if you ask for it directly. Especially since it is important to know the actual wattage so you don't accidentally blow a breaker with a presumably high-powered light.
Actual "Consumed" Wattage: 92.8W
New "Calculated" LED Consumption: 1.5 Watts
With just with one clarification, we reduced the power down by over two thirds! And that is strange, for our fancy 5 Watt LEDs that I paid extra for, we are running them at only 1.5 Watts? If we compare this panel to a panel with 3 Watt LEDs, would we see any difference? Probably not much.
Testing the True LED Power Consumption
When we open up this BV301 SAIDI Red Light Panel, there is a lot of guts inside other than just the LEDs.
Even though we know know the actual consumed power for this panel is 92.8 Watts, not all of those watts are going directly to power the LEDs!
Some power goes to:
- The power adapters are not perfectly efficient, meaning losses in watts.
- The two cooling fans require some wattage.
- There are naturally some losses along wires and circuit boards.
So I went in with my multimeter to test the actual voltage and current being used to power the LEDs themselves.
I found the following:
Red LED: 2.39 Volts, 0.69 Amps
NIR LED: 1.6 Volts, 0.66 Amps
To find the actual LED watts, we simply multiply the Volts times the Amps.
Red LED: 1.65 Watts
NIR LED: 1.05 Watts
So each LED consumes either 1.65 watts if it is Red, or 1.05 Watts if it is Near-Infrared. It is interesting to note that the Near-Infrared (NIR) LEDs consume less power than their equivalent Red bulbs. And once again we are getting very far away from that 5-Watt rating, especially for the NIR LEDs.
Considering we have 30 Red LEDs and 30 NIR LEDs, we can easily calculate the actual LED power.
Total LED Watts: 81.18 Watts
Even though it is easy to obtain the Actual consumed power for a panel by asking the manufacturer or using a Kill-A-Watt tool, we need to break into the panel itself and measure it with a multimeter to know the true LED power.
Even in this case study, with an actual consumed power of 92.8 watts, yet the LEDs are only consuming 81.18 Watts. So we can see how these power adapters and fans also can confuse the situation of how we analyze the LED power.