This is a remix of https://www.thingiverse.com/thing:1603228
I changed the screw to be a #8 screw and added a countersink for M5 washers to add some strength to the mounting.
Holds my rather hefty 7.5 Amp/Hr battery without issue.
Printed w/ Prussament PLA, std settings and 15% infill standing up on the bed like it would be mounted on the wall.
The author hasn't provided the model origin yet.