Orion TR 12 12 30 versus SX 50 for tear drop trailer

My trailer has a115 AH AGM battery. My tow vehicle has a 110 Amp smart alternator. The TR 12 12 30 seems the right choice but the smaller size and lower heat generation of the SX are very big advantages in my tiny trailer.

I would prefer the smaller cooler SX but am concerned it is overkill for my application

Can I limit the charge amperage on the SX to < 30 amps to replicate the effect that the TR produces? Are there other considerations?

Any help or recommendations would be appreciated.

Yes, you can set a lower current limit on the Orion XS.

I would recommend the XS.

Thank you. XS it is.
And now an installation question.
Can I use the car’s frame as the return to ground as shown below? This would eliminate installing the black wire all the way from the connector plug near the hitch to the car’s battery. It would rely on the existing battery ground wire to the engine and a shortish wire from the plug to the rear of the frame.

Good idea? Bad idea? OMG don’t do that?

John

I couldn’t get my illustration loaded here so I will try to describe it.
Hot wires (red) as shown in Victron manual with a plug connector at hitch for wire from input fuse to XS input.

Existing start battery ground to engine.
Ground wire from frame at rear to plug connector.
From plug to output battery continuing to XS output.

I hope this makes sense.

John

Oops. ‘continuing to XS ground” not “output/.