In the name of scientific research, I bought and disassembled the popular 20w IP65 plant-grow light to check for wattage and heat.
I removed the power supply for the temperature measurements, because I only wanted to get the heat from the LED, which was a LOT.
It turns out that the LED is getting .59 X 22.8 = 13.5 watts
As thought, the Chinese LEDs are labelled higher than their "real" watts. However, it is still a tremendous amount of heat and light. The back of the case, and the front glass, get too hot to keep your hand on. And the LED lens itself gets sizzling and will burn you.
Overall, even though it's not CE or UL rated, it's a good splash-proof light for the money. Just don't drop it in the water, because water will get inside and short the line voltage there.
More pics in the following post...