I have an Alienware M17 R3 that normally runs on a 250W brick and it refuses to boot when connected to a 100W source. It’s a BIOS option I can disable, but it’s pretty telling. If I switch to USB power when it’s already running, Windows makes similar complaints about insufficient power.
I don’t have any USB-C sources bigger than 100W, but I suspect it would complain even at the 240W maximum @lizard-of-oz mentioned given the 250W brick. But on the plus side, the brick is only 2000% bigger than a matchbox, which is something, I guess…
