What components do you recommend

[DeeBee]

I'm starting to put together a parts list and found I was missing a few key pieces of information.

The plan is to have AGM for start battery and LifePo4 for House (12v)

I'm going to have two separate solar panels, one for the house, one for the engine. (probably)

Currently there is an AC->DC charger (old) and an alternator available to charge the batteries.

I would like to setup the following.
The engine battery will be charged using this priority: the Alternator; Solar; Shore power; jumper cables from house (unless a B2B is required)

The House battery will be charged using this priority: Solar, Shore power, jumper cables from engine w/engine running (unless a B2B is required)

I expect to have a PWM between solar and Engine battery and MPPT between solar and House.

I've looked at Automatic Transfer Switches but they appear to be on the load side not the charging side. Maybe I missed something. I'm trying to isolate the two systems as best as possible (personal preference, please don't judge).

Suggestions are appreciated.

[DeValency]

Originally Posted by DeeBee

I'm starting to put together a parts list and found I was missing a few key pieces of information.

The plan is to have AGM for start battery and LifePo4 for House (12v)

I'm going to have two separate solar panels, one for the house, one for the engine. (probably)

Currently there is an AC->DC charger (old) and an alternator available to charge the batteries.

I would like to setup the following.
The engine battery will be charged using this priority: the Alternator; Solar; Shore power; jumper cables from house (unless a B2B is required)

The House battery will be charged using this priority: Solar, Shore power, jumper cables from engine w/engine running (unless a B2B is required)

I expect to have a PWM between solar and Engine battery and MPPT between solar and House.

I've looked at Automatic Transfer Switches but they appear to be on the load side not the charging side. Maybe I missed something. I'm trying to isolate the two systems as best as possible (personal preference, please don't judge).

Suggestions are appreciated.

All sounds good. The only concern I can think of is that MPPT may not be a good enough controller and current limiter between the cranking batt and the LFP in order to protect the alternator. Most experts I have discussed with also recommended a B2B charger.

[dmdelorme]

I would pick an epsolar charge controller for the house and a keep both panels for the house. and use the engine to charge the starting battery. LifePo4 need special charge settings and no float and no equalisation. I would do more reading about using the alternator with the LifePo4. It needs a decent BMS to prevent charging when it is cold etc. they are very different agm and LifePo4 and need different charging settings.

[DefinitelyMe]

I'm also wondering why you need to charge the starter battery with solar? Do you plan to leave the boat sitting for months at a time? Much better off using the available solar capacity to charge the house bank. The starter bank should never be discharged and will get topped up every time the engine runs.

[mitiempo]

We need to know more to give good answers. What Lfp cells - how many AH?

What alternator - AH rating? What external regulator? You want every item as adjustable as possible.

What kind of boat and what kind of daily usage is/will there be? That determines how much you have to put back.

In general recommendations:

Balmar alternator or equivalent.

Balmar MC-614 regulator for above.

Victron Smartsolar MPPT controller - fully adjustable in every aspect and bluetooth to your phone with history.

[DeeBee]

I've found an awesome YouTube channel that has some pretty good description of what all the components necessary/optional.

Pacific Yacht Systems - Jeff Cole.
Specifically the whole series titled How To: Marine Electrical Seminar - Power sharing & monitoring (12 episodes ranging in length typically over an hour each)

BTW - the question of why solar to charge Start battery is if the engine is not started for a few weeks I want to keep the battery topped off.