Anker SOLIX C300 DC Base

This is a 200mm x 200mm x 60mm (45mm internal wall height) base for the Anker SOLIX C300 DC Power Bank Station. When we travel in the car I just bring our Power Bank Station along and have the kids plug their electronics since it has higher PD. Also doubles as a nightlight if needed in the hotel room. Only problem is it's very top-heavy and slick so it falls over and slides around a lot in the car. I made this base for it to slide into and put a few adhesive velcro feet on the bottom so it stays put on the carpeted floor mats. Took it for a spin this weekend and it didn't budge.