A couple years ago I bought a pretty kickbutt laptop, a Razer Blade. Since day 1 the battery has drained completely in 2-4 days, while being powered off and unplugged from the power supply. I just lived with it & thought it was “normal”. This morning when I pulled it out to do some work on it - dead again. So I did some cursory innerwebs searching.
There’s a BIOS setting to “Enable USB Charge Function” which was enabled from the factory. It turns out this is the culprit ( or at least I believe it is ). Configured this way from the factory. Setting this to disabled is evidently the fix, I’ll know in a couple days.