I have one of the first Thinkpads to have a USB-c socket, and the PC can be recharged slowly that way using a low-wattage adapter, but then it will not draw any power at all from the charger when you turn the laptop on, you get a message informing you of this.

Install the BIOS update. after my update it charges on everything except a 5V only adapter, although it doesn't tell the OS it's charging unless it's on a 45 watt or more supply.