I bought these a while ago and thought I’d make a quick video about them while the lithium pack featured in recent episodes was being charged in a non-compliant manner.
The neatest thing about these lights is that the series resistor (100 ohm) is inside the USB plug itself, and has been chosen to run the LEDs at low current (about 1mA each) which will result in very long runtime and operational life. The resistors dissipation is also low at just 40mW (0.04W).
This style now seems to have been replaced almost completely by the newer copper-wire based LED strings and for some reason the seller’s profile would not show up on eBay.
As mentioned in the video, these lights are best run on small power banks that shut the output off completely when the internal cell is running low. Some older power banks just turn off the boost converter and the lower cell voltage will still continue to run the LEDs at lower voltage with the risk of over-discharge if left in that state continuously. The use of the smaller packs with 5V on the output continuously is preferred as the bigger “intelligent” packs may just shut off the output with such a low load and will also probably draw more current for their own internal electronics than the actual LED string.
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