Dual chemistry Sailboat - Charging configuration

[Barold]

Looking for opinions -

Current Config:

• AGM start, AGM House
• Both combined through Isolator to Alternator; Individual wiring from Shore power charging (40A), set to AGM profile

Proposed:

• AGM Start, LFP (280AH) House
• Alternator to charge Start only
• Start wired to Orion TR DC to DC Charger to House
• House bank disconnected from Shore power; wired to MPPT Solar and Orion DC to DC Charger

Rationale:

• Alternator protection (in the event the BMS disconnects the house bank while motoring)
• Charge voltage customization for house bank management - Shore power has multiple chemistry profiles but can only select one at a time. AGM Float 13.6V max , Bulk (can disable) 14.4V max 2hr; LFP Float 13.8V and Bulk (can disable) 14.4V, up to 16 hours
• Orion can play double duty to pass charge from shorepower and alternator to house bank

My Question

1. Am I over complicating things by adding the Orion - It's a 30A charger so it may not be up to the 40A potentially from the shorepower charger (which means I might have to use the sterling 50A B2B charger).
2. Are the charge profiles on my shorepower charger close enough that I can just use the AGM profile (13.6V Float or 14.4V Bulk and 13.6V float) to apply to both the LFP House and AGM start batteries (I suspect not)

 

[Danny]

I have a mixed system using a Sterling BB1260. I can show you my system where I have the option of using the shore charger and the Alternator to charge the house through my BB1260. My system diagram is at 2:55 on the following video.

. I have a link to an important article by Rob at marinehowto.com in video notes. I would not trust your shore charger when you are not looking at your battery voltages unless you use a b to b charger in the middle. I have many other videos of my project here is the playlist https://www.youtube.com/playlist?list=PLCal7Co3mAHQqNPvlWpqVh61g_8AVA69q. It is a big undertaking and this takes a lot of testing. I had issues with connecting my negative LA bus with my Lifepo4 negative buss.