Dell USB-C docks and the Precision laptop range.

dell-universal-dock-d6000-02-pdpSo the Dell Precision 7520/7530 has a USB-C port.  Which you can plug a Dell USB-C dock into it.

And it works well.  Until you close the laptop lid and the laptop decides to Hibernate.

“It’s faulty”, I say to the Dell Engineer.

Some thinking later, the Dell Engineer responds

The Precision laptop requires 180W of power to charge the laptop.
The USB-C output is at a maximum, of 100 watts.  Notice how the battery icon shows that it’s not charging?

The solution, in the words of Dell:

“Systems docked via USB 3.0 Type-A connections or systems that require more than 65 watts power input to power the system and charge the battery will require a separate AC power adapter to power the system and charge the battery.”
Dell Universal Dock (D6000) system charging limitations

Plugging the USB-C dock into the USB-C socket will still allow you to use the dock.

Just not charge from it.