this post was submitted on 17 Mar 2026
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Lenovo USB-C PSU for laptops powers a Rasberry Pi, but cannot simply charge bicycle lights. WTF? (external-content.duckduckgo.com)
submitted 1 week ago by evenwicht to c/askelectronics@discuss.tchncs.de
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I bought a 2nd-hand Lenovo USB-C PSU (ADLX65YLC3D) which indicates a range of voltages (20v, 15v, 9v, 5v) on the label. Tried to charge a few different bicycle lights but the charging indicators did not light up on any of them. I almost tossed it because the 2nd-hand market I bought from is definately dodgy. But then I tried to power a Rasberry Pi and it seems to work on that. So wtf? An a/c adapter either works or it doesn’t. What would cause this: works on some devices but not others? The Rasberry Pi needs 5v just as the bicycle lights. That is the default voltage for USB-c.

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[–] evenwicht 2 points 6 days ago (1 children)

They are actually headlights. The kind that strap to your head, which I happen to use for cycling. I suppose they were intended for joggers. I don’t know the makes but it’s two different manufactures, likely some cheap chinese stuff. One is an LED strip across the forehead with a side beam, 7 or so different functions with different colors and intensities. The other has selectable red, white, or yellow colors, blinking or solid.

[–] FartsWithAnAccent@fedia.io 1 points 6 days ago

Zebralight makes some good stuff headlight wise, and pretty sure Sofirn or Wurkkos would have some more affordable stuff.