Top critical review
Deceptive LED Power Rating / Poorly implemented USB port
Reviewed in the United States 🇺🇸 on September 22, 2020
The Amazon product page of this product says "JUKSTG 36pcs LEDs 14W 7 Dimming Levels Table Lamps". On the box it also says "LED 14W". Naturally one would expect that the LED lamp is rated for 14W. But that's not the case.
According to my power meter, the actual power consumption for this lamp is:
- Max Brightness: 6.6W - 6.9W
- Min Brightness: 1.0W
- Standby: 0.5W
As you can see, the LED light portion consumes just 6.1 - 6.4W, not even half of the suggested '14W'.
But where did this '14W' number come from? As it turns out, the AC adapter is rated 15V 1A. That means the maximum input power to the desk lamp is 15W, which includes power for both the LED light and the USB port.
The USB port is rated 5V 1A, but it is very poorly implemented. When charging my cell phone, the output current starts from ~1.2A initially. But within a few minutes the output voltage drops to ~4.7V, while the output current drops to just around 1A. Evidentially the USB power converter inside is overheating and losing regulation.
As can be seen from the picture I uploaded, the output power is 4.72V x 1.01A = 4.8W, but the input power is 9.9W. That means there is about 5W power loss in the converter. After just 5 minutes of operation, the back of the lamp unit near the USB port already becomes uncomfortably warm. I really worry that if I leave it charging my phone for too long, the power converter will eventually burn out. For now I'll only use it to charge my Fitbit or wireless earbuds.
As an LED desk lamp, this unit works reasonably well. However, due to the deceptive LED power rating and the poorly implemented USB port, I cannot recommend it.