I've got a few USB-C chargers that can deliver power via USB-PD; a 65W charger, a 100W charger, and a hub that advertises "PD Passthrough".
My laptop accepts up to 100W, which is why I'm surprised when I plugged the 100W charger into the hub and try to pass it through, I see this "More Power Required" message:
Is there a way to see what my laptop has "negotiated" the power draw from the device?
Using a USB type C current meter (like here) between the laptop and it's power cable, you should see the current it's pulling. Multiplying this current by the voltage tells you it's power in watts.
Thats pretty much all you can do on a hardware side to get the actual physical current being pulled by the machine. Software readings can't always be trusted in cases of faulty components (to name one example) where readings might be wrong.
These USB meters are fairly cheap and I got one for about £4 on Aliexpress, at the cost of waiting a while for it.
