Reworked the Original STL to have rounded corners on the build plate (less prone to warping). Cut some holes in the model so it uses less filament (print time remains more or less the same).
EDIT: Original Model owner has uploaded the STEP file which I then used to redo my adaptations and fix a minor overhang error. Uploaded the STP and STL file.
EDIT II:Made a version the does not latch the battery in place. As the battery is under an angle and slides to the wall anyhow, I find it easer in use to not latch the battery.
My Onshape link is HERE
The author remixed this model.