Solar Charger & Truck Power Question

My reason for considering having a charge controller between the truck and the camper is because I want to charge my AGM batteries with a charger that is specifically designed for AGM batteries and is tied directly to them instead of 30+ feet of wire from the alternator on the truck and mixed with the starter batteries. My Solar Charge controller lets me set the battery type, my alternator does not. The camper batteries Bulk, Absorption, and Float charging needs will be completely different and the truck batteries and the alternator isn't going to know what is happening with the two different sets of batteries, it's just going to try to put out a constant voltage. Adding the length of the wire and whatever voltage drop is occurring there plus all of the load the alternator has from the truck itself I believe is leaving the camper batteries at a disadvantage for charging properly. My solar panel is only 60 watts so it isn't quite capable of handling the charging needs all by itself so I have to rely on the truck for topping off while on the road.

One point of clarification... Yes, the truck and camper batteries are wired together but only temporarily as the solenoid used to cut power when the engine is off went bad and needs to be replaced.