While you have a large bank that will go a long time before charging
You do not have any way to charge:
A. bulk rate of at least 200A @12V
B: long enough to fully charge the bank to full float level.
Both requirements to get the full life from AGM's
So while it sounds like a good idea to have a huge house bank, it's not always so good..
The loads should be matched to the size of the bank and to the charging
Realize that we are talking optimal procedures here, but optimal procedures will produce the longest life.
It's all about choices and how frugal you need to be.
Even using a generator
your bank could take over four hours to charge.
You could use a smaller bank or stay with FLA batterys.
The thing is that for AGM's, wandering around at 60 to 70% will kill them quickly. There is no magic to AGM
batterys unless you can charge them at a higher rate saving time or need to save a small amount of weight.
For me they have more power for the limited space on the boat.
Now if you need to have sealed batterys and very light weight, look at the LIFEPO4
stuff but that is cubic yards of money
. That means a new generator
and controls and maybe a whole electrical system
For me that would make sense with a new build, planning everything around the batterys. You have to realize that a new technology is only good and wonderfull if you can reap the benefits.
A: longer life
B: greater safety
, sealed system
C: Quicker charge
D: lighter weight (mostly LIFEPO4)
When you stick new cutting edge batterys into old antiquated control / charging (slow) systems, all you get is a huge waste of money
Engineering is about matching apropriate components.