USB power through battery compartment

[PeterP]

Hi, I am thinking of providing a power to my calculators in the display, especially the 41CY and the RamBoxes so that they keep their operating system.

It would be visually much nicer if I can do this from the back rather than via cable into the Module Ports like Diego's USB-Module Power.

Is there any reason not to fashion something from a USB charger / USB port to the battery contacts directly? I am thinking of using one of the 3D printed Battery compartment replacements, with a hole in the middle through which a USB cable can be sent through, which then is connected to the battery terminals of the calculator. As such the display case would not show any cables. if done well, it could also be detachable easily so I can take out the calculator to show to someone.

Would be great to hear the advice of the EE-geniuses here on what protection if any I should think of, or why that would not be a good idea.

Thank you!