question

I assume that you have a busbar onto which the Orion output, and the battery are connected. It’s no problem to connect a separate charger on to the same busbar, to charge the battery when the engine/alternator is not running. Just use the correct wire size and fuse towards the busbar.

And of course, set the charger to the correct settings matching the battery specifications.

A busbar is a metal plate with bolts and nuts, on which you centrally connect all your 12 volt devices.

You have both a busbar for all the positive and for all the negative connections.

The Victron battery you have, has an internal protection for overload. Using an extra Victron Battery Protect is therefore not mandatory, as long as you respect the maximum load- and charge currents.

Install the 12V+ and Ground busbars on a central position in between the 12 volt installation.

Then connect all 12V equipment with their 12V+ and Ground on to those 12V+ and Ground busbars.

Because each 12V device needs a protecting fuse, you can also use a Victron Lynx Distrubitor. This is a 12V+ plus Ground busbar, and fuse holder in one box.

Maybe it’s wise to investigate the Lynx Distributor schematics on the Victron website. At this moment I’m not to convinced that you have all the knowledge about this kind of matter… Maybe we’re talking about safe low 12V voltages, but the high currents can cause a lot of troubles, and high risks, when things are not properly connected, and protected.

As an extra tip: take a look at the YouTube channel of Explorist Life, they have a lot of simple to understand beginners tutorials for 12V RV installations.