A few thoughts and replies to get you started. 

First, no question you can mix and match brands, particularly between power distribution and conditioning (inverters, chargers, MPPT, DC-DC, etc) and batteries. In fact, there is nothing to say every component couldn't be a different brand. But, staying within a brand, particularly Victron, gets you communications between the components and from components to a GX device that allows monitoring and coordination of the system's functions.

Before tearing the battery apart, I think I'd start with a capacity test. If you don't have a shunt, I would invest the little more than $100 and add a Victron SmartShunt to your boat. That will let you understand what's happening with the battery. You can do a capacity test by putting a fixed load on the battery and seeing how many amp hours it provides.

Victron's NG batteries are amazing. But, they're also premium batteries with a higher price point than some. I think they're a great value, but if the priority is on controlling costs, you can likely get the capacity you need for less.

-Ben S.

@ben-stein I bought the Epoch V2 Elite 460Ah batteries.  Rod Collins recommended them.  I had wanted the Victron NGs but those are much more expensive.  One thing I was hesitant about was the integrated BMS that many batteries have.  The Victron does not have that, the Lynx BMS is a separate component.  I would have thought that a separate BMS would be better since if it dies, it can be easily replaced, even carrying a spare could be possible depending on how remote you were going to be.  An integrated BMS dies, and you are minus the entire battery until you can replace it.  This after shipping it back and arguing about the warranty coverage.  As usual, I find myself second guessing the decision.

@ben-stein

I am replacing my LFPs, having just purchased Epoch V2 Elite Series 12.8 V, 460Ah batteries, two in parallel.  After reading everything I can find that looks reputable, like Marine How To, the Blue Sea and Victron sites, and Calder, I am settling on the following system architecture for my 12V system.

Operation Underway

I am thinking now that, while underway, I should run both engine alternators into the house LFP.  These would be Balmar's, or equivalent, with the appropriate external regulators, and protection from LFP load dumps, to replace my current stock Volvo alternators.  We also have 1200W of solar that also feeds the LFP bank.

The engine start batteries will be Lifeline deep cycle AGMs that will be maintained by a Victron DC to DC converter, the new Orion XC 50s, maybe.  I may use a separate start battery for each engine, and use the port engine battery to start the 11.5 kW generator.  One reason to have separate start batteries is for emergency back up power in case the house LFP disconnects for some reason.  This would keep instrumentation alive for a while.  A Blue Sea 5511e battery switch can be used to bring the AGM on line and enable charging the them using the generator until the LFP problem is sorted out.  The generator would supply the inverter, which would passthrough to the battery charger.

Operation at the Dock

I would like the system to be capable of operating using European shore power.  I would like to take the boat across the pond someday soon.  At this point, it looks like that requires a separate battery charger for the LFP house bank.  This charger would get its AC input from European shore power at 230Vac, 50Hz, and also from the generator, which would be 120Vac, at 60Hz.  But the charger won't care.

To operate the AC loads on the boat, we would use the inverter to supply 120Vac at 60 Hz, taking its input from the house LFP bank.

I'm doing this because it looks like the Victron inverter/chargers cannot operate on European shore power.  Their specs have voltage ranges for both single (L,N,G) and split phase (L1, L2, N, G) supply, and I think that European shore power is single phase.  The maximum voltage for single phase is less than 200 Vac.  I may be misunderstanding the specs.  I'm just a gearhead.

We have a Pronautic 1260P charger on the boat, so I may go with that since it still works, and I think it is programmable for LFP.  I have to check it so see if the absorption time can be limited, and the storage voltage is right for the LFPs.

I came to these conclusions after reading that the typical architectures that Blue Sea has on their website show automatic charging relays of some type.  These don't work with LFP batteries.  I think this is also true of the Victron Citrix devices.  I my be wrong.  But this is why I settled of running all the charging machines into the LFPs, and maintaining the start batteries with the Orions.

I may also power our 1500W windlass off its own AGM battery to eliminate 30 ft of wire running from the LFP.  This might have to be another smaller LFP assuming that the power needed has to account for hauling in the anchor and 300 ft of 3/8 chain.  I might have read from Dashew, or maybe Naranjo, that with 300 feet of chain, you can anchor pretty much anchor anywhere.

So, I'm out of my lane on all of this.  I would greatly appreciate opinions on my plan, any help I can get.  Thanks, very much.

Rich

Rich,

With externally regulated alternators I would definitely land them on the house bank and then use DC-DCs to send charge to the start batteries. Personally, I really don't like sharing a generator battery with anything else. I view a generator as your ace-in-the-hole and don't want to end up in any scenario in which the generator battery is dead and hence won't start it.

For world power capabilities, take a look at what BoatRX did with this system: https://panbo.com/a-cool-and-quiet-sailboat-thanks-to-efficient-air-conditioning-lifepo4-batteries-and-integrel/. In general, I think you're on the right track with using battery chargers, batteries, and the inverter to accept a broad range of power sources. The BoatRX approach with a European spec inverter and an autoformer is a novel approach I don't see very often. 

If you do use a dedicated battery for your windlass and select LFP, please carefully consult the inrush specs for the windlass. Those numbers can be shockingly high for DC motors. 

-Ben S.

@ben-stein Someone suggested running my stock internally regulated Volvo alternators to their respective AGM start batteries, not to the LFP house battery, in order to not have to replace the expensive alternators.  I can still get by because we have 1200W of solar, and an 11.5kW generator, which he noted was very big.  Also eliminates the DC to DC victron converters.

Another person noted that I may be able to disable the regulators inside the Volvo alternators, and add an external regulator to replace it.  I have never heard of this, and is sounds like hokey surgery.  Like an alternator lobotomy.

What do you think of these suggestions?

Ben,

I am now wanting to keep the current alternators I have, internally-regulated, stock Volvo 115A units.  I was planning on starting them with AGM batteries and charging these with the engines, so the alternator circuit will be separate from the Epoch LFP bank.  I was going to use the Blue Sea 5511e battery switches for the emergency combining feature so that I can support critical loads while underway with the two AGM start batteries, or start an engine, or genset with the LFP if an AGM is dead.

This parallels the Epoch bank with an AGM but only for emergencies.  Rod Collins also wrote that he would remove the LFP fuses while the batteries are combined.

Do you think this is an acceptable practice?  Will it protect the alternators from an LFP load dump?

I am also planning on adding a Victron Phoenix 3 kVA inverter.  I don't see anywhere the type of fuse it requires on the DC feed.  I thought it was recommended to use a Class T for inverters.  Is this true?

Last question, for now, I was going to maintain the AGM batteries with the LFP house bank by using a Victron Tr Dc/DC converter.  Living on the boat through Annapolis winters, the start batteries go flat with no way to charge them.  It also charges the start battery if you have to crank excessively to get the engine started.  After replacing the fuel system, filling the Racor, and bleeding at the engine, it still took some cranking (less that 2 minutes total), but the battery was connected to a DC/DC converter, so it didn't get drained.  What do you think of this part of my plan?

Thanks again.  This has been a great help.

Rich