NetBSD 1.0 runs down battery

[KC9UDX]

I don't expect the cable knows anything!  It's just wires and terminals.  I don't know right off hand why it wouldn't have a direct power connection, like the AC adapter power supply that supplies the same 5V.

Some cables actually have chips in the plug ends.  USB-C charging is capable of negotiating charge rates, and that must happen (if it does) in the cable or the wall wart that the cable plugs in to.  The PBP does *not* negotiate USB-C charging rates in hardware.  I don't know if Linux might tell a smart charger plugged in to USB to turn on.  But such a device, if that's what's happening, should generate a message when NetBSD does or doesn't recognise it, I expect.