In most cases, laptops require a minimum wattage in order to accept a charge from a USB-C source. Modern laptops generally conform to USB power delivery standards (USB PD), which is a uniform standard of charging. To determine what USB PD voltages your laptop is compatible with, you should be able to check underneath your laptop, to see which PD voltages it supports. Most laptops will require a minimum of 20-30W to initiate charging and can draw as much as 100W through USB-C.
The Omni 20+, Omni 20c+, Omni Ultimate, Omni Mobile 12,800, and Omni Mobile 25,600 all conform to USB-PD standards, and can provide up to 60W output, which is enough to charge all but the most high powered USB-C laptops. The Omni 20c+ can output up to 100W from one of the ports and can power high powered USB-C laptops like the Wacom Mobile Studio Pro, and the latest 16" MacBook Pro.