This is a simple case for the PowerWatcher 3 along with the RS485 voltage module and current sensor.
Boards are mounted using M3 bolts and washers, self-tapping into the plastic, do not overtighten.
Lids are friction fit, so you may have to over/undersize the lid just slightly for a good fit depending on your printer.
Use support for the vertical versions (printed flat).
Lids print well face down without support or you can print face up with support.