Newbies need Lithium help please.

[mcon12000]

Originally Posted by CatNewBee

It all starts with the battery my friend. Inverter and charger almost make no sense if you not have the appropriate battery capacity. You could wreck your FLA battery with a large inverter quickly, while a LFP would not even sweat.

All components must play in the same league.

I agree with a portion of that statement and his FLA bank would need to be sized appropriately and I made an assumption that it was. Where I disagree is that a modern inverter/charger and alternator can be easily programmed for FLA. He could reprogram for the charge profiles of both when he determines what lifepo4 battery option is best for him. So its money well spent installing a system thats flexible.

I don't have the breakdown of the $19k but I'm betting theres a healthy markup on the batteries and I believe he mentioned that the lifepo4 bank they offered was smaller than what he could secure for similar money. Many of the other components are going to exist regardless of FLA or Lithium. This makes upgrading or swapping those components more affordable during the build process. Later on he can spend $10k on something with twice the ah of what they are likely offering. Make sense?

[CatNewBee]

A large inverter on a small FLA bank is a no-go, an oversized charger is nice to have, but will be of no benefit, because the current is limited by the acceptance of the battery, it will still take a long time in bulk and absorbtion.

Of course you can build the system step by step, but you get most of it starting on the battery and adding the components later, you can use the benefits from day one even with the old stuff if you are a little careful or have a good bms. This is the option where you immediately see an improvement on your energy situation, if you start with the electronics, you only see nice boxes and gages.

But this is only my opinion, it may vary to yours.

[FerrariSailing]

As you are on a cat then you must be weight conscious always.
I have recently gone from 2x200ah AGM house to 1x300 lithium which was roughly half the weight of 1 AGM. I still have 2 lead acid start batteries and use the original alternators plus 800Watt solar. I had to have 2 new chargers fitted and some wiring changes, all up $6700AUD on the Goldcoast. Im a sail cat don’t motor a lot I run 2 fridges 24/7 plus auto helm and all other stuff off the lithium and it’s so good I don’t always bother to hook into power the odd time I use a marina.
Go lithium always, its superb and ticks all the boxes for a multihull!
Roger

[Auspicious]

Originally Posted by FerrariSailing

I have recently gone from 2x200ah AGM house to 1x300 lithium which was roughly half the weight of 1 AGM.

That's not much battery bank for cruising.