Modification to the power meter box from Andreas Spiess (https://www.thingiverse.com/thing:2789890/).

To get rid of the need for an external cable I added a switch to connect the green plug to the red one for voltage measuring. To make room for the switch I moved the power switch to the side.

I used Fusion360 to convert the original stl to solid and make my modifications - my sources are included for further modification.

Watch Andreas video for more detail: https://youtu.be/ffLU7PSuI5k.