Charging options for boat Lithium house bank and AGM engine bank

[magnesium]

All charging systems (alternator, MPPT, and shore power) should be setup to charge the house LIFEPO batteries. This will take advantage of their efficiency and rapid charge rates.

Well, IMHO, this will kill the alternator when LFP reach its full state of charge because LFP must be fully disconnected from any charge when full.
It would be better to charge starter battery (lead, AGM) from alternator, then route charge to LFP pack with a Cyrix Li-CT on the positive charge bus bar of the LFP. And from any other producers like Solar MPPT, shore power, to charge directly (with respective setting adjustment for LFP) to the positive charge bus bar. Then, having another positive bus bar for consumers devices, you avoid any interference of charge and discharge and keep LFP and alternator in safety.
Supposing alternator can deliver all the amps LFP will absorb... If not, using a DC-DC battery charger will protect alternator if it is not thermally or over current protected.

 

[ERNWA]

Well, IMHO, this will kill the alternator when LFP reach its full state of charge because LFP must be fully disconnected from any charge when full.
It would be better to charge starter battery (lead, AGM) from alternator, then route charge to LFP pack with a Cyrix Li-CT on the positive charge bus bar of the LFP. And from any other producers like Solar MPPT, shore power, to charge directly (with respective setting adjustment for LFP) to the positive charge bus bar. Then, having another positive bus bar for consumers devices, you avoid any interference of charge and discharge and keep LFP and alternator in safety.
Supposing alternator can deliver all the amps LFP will absorb... If not, using a DC-DC battery charger will protect alternator if it is not thermally or over current protected.

You are correct. I carelessly left out my plans for alternator protection. I was planning on using a victron argofet battery isolator so both the LFP and starter battery will be receiving charge from the alternator. I would also consider doing as you suggest with the DC-DC charger pending alternator output potential.

Thank you for your thoughts.