Sollution to Mount the Charger of your Smart Watch on the Side of a 13mm Board - Just Slide it on to the chosen board , wall, shelf, ,… whatever has a stight wall. 

If printed in somethine other than PLA it should just grip on there pretty well. I printed mine in PC-CF.

I include two versions of the model. One without and one with a hole to help release the charging base if it might be a bit tight, the tolerances are quite small.

Also included is a parametric Fusion360 file to adjust the thickness of the plank you want to mount it to if desired.