Increasing charge rate from TV to TC?

~DJ~ wrote:
It is my understanding that the amount of charge going to the truck camper battery is determined by how much the alternator needs to send to the truck battery. So if the truck battery is nearly full the camper battery gets very little charge.

Not like that. Alternator just provides a voltage. Alternator does not know where the power goes or how full any battery is.

Alternator generally does start a bit high in the mid 14 volt range and as the alternator warms up along with the entire engine compartment the voltage usually drops to the mid to high 13s. The alternator holds this voltage continuously while running.

Yes the engine battery seems to charge first and long before the house battery. This effect is mostly because the charging cables are not balanced, not even close. The connection to the start battery is short and fat. The connection to the TC house battery is long and thin. And the start battery is only discharged a small amount vs. the house battery.

To get more charge in the house battery you need some big fat wire to equalize the voltage. Also the house battery will take several hours to charge and the alternator may not hold voltage up in the 14s for the entire time causing the time to charge to be extended.