If I have a 2nd aux 12v battery in my car that I need charged with the correct characteristics (Li-ion) I can choose to pick the MPPT (12v) and connect solar OR orion (12-12) and connect it to alternator DC 12~14.4V.
If I wanted both, would I need both? What stops me from feeding alternator power to the solar in on the MPPT? Aren't these the same chargers with another name?