Dell XPS 15 9500 USB Charger

Hello! 

One very important reason I bought Dell XPS 15 9500 was the USB C Power Delivery. As I travel a lot I wanted a laptop that I could charge from any USB C PD charger. Unfortunately I didn't get what I expected. Is there any charger that is portable like the new GaN chargers and can charge this machine adequately? 

I have read mixed reviews regarding RAVpower 90w but I am not sure if I should invest in that or sell this machine and get a macbook.