I had purchased a HD20 from Wurkkos a while back. It has satisfactory performance, especially considering the price. However, I would like to bring into attention a possible major design issue (or it could be a one off defect) with the USB-C charging implementation. To be clear, Wurkkos customer service had provided me a steep discount on another purchase as a compensation, which is satisfactory to me, so I’m not requesting any action from Wurkkos for me here.
Several days ago while I was charging the drained 18650 battery inside the light with a USB charger, I noticed through my USB power meter that it was drawing a somewhat large current (5V ~2-3A) for the 18650 (maybe it is intended for the 21700). I decided to unscrew the battery tube from the light head (the part containing the USB port), and then I tried to turn it on to see if it is able to run without a battery from USB power. After turning it off and on like this a few times, however, it started flickering, and I noticed an unexpectedly large current draw (5V ~4A) while the light is turned off in this state. I quickly unplugged the USB connector, which was very hot to the touch, and I can smell burnt plastic in it. A few hours later, I decided to try using it to charge my battery again. This time, a plume of smoke came out within seconds of me plugging it in, and the USB meter turned off, which I assume indicates that the power pins are shorted. The light still seems to work as normal in all modes with a charged battery, other than the broken charging functionality. In addition, the head of the light appears to have some loose parts rattling around when I shake it, which was not present before, which I can only assume to be some plastic that came off with the charging module.
Anyone else with similar experiences? If you have an HD20, I would suggest that you do not attempt to remove the battery tube while it is plugged in, and do not try to use the light from USB power.
I had charged it successfully before using the same power brick (65W, 3 port, GaN charger supporting PD and QC), so I would not think this is a defect on my particular unit. Interestingly, I faintly remember that it used a different PD mode on that attempt (either 9V or 12V, at low currents – can anyone here confirm?).