Anyone test external Laptop Battery packs yet?

This was on sale recently:
GOLABS R500 Portable Power Station, 518Wh Outdoor Solar Generator LiFePO4 Battery Backup with 500W Pure Sine Wave AC Outlet, PD 100W USB C Quick Charge for CPAP Camping RV Travel Emergency Orange : Amazon.ca: Patio, Lawn & Garden

“Portable” is relative…