4 bank system - 2 house, 1 inverter, 1 start back-up - please comment - Thx

[RockOn]

Folks - planning a system for a 40' aft cabin live aboard.
Goal is to have all my systems available for 5-7 days - minus AC, oven, and Hot Water heater
I've done the calc's for usage so solar panels (3 @ 370w) and batteries will be sufficient.

Please take a look.

My pref is one isolated system to feed the whole boat with only 2 connection interface (inverter to vessel ground and 110v to a 2 position switch)
- keeps 4 banks charged
- keeps components down
- keeps system separated from current house set-up for easier install
- downside loose some efficiency from charging DC to 110 to DC
- leaning towards the 3000w inverter bank being 24v (lower MPPT amp and also better to feed to inverter?)
- I do not always have to have Battery Charger on (can turn off at the panel and leave on for several hours mid day as needed)

2nd page is more tritonal set-up with a system for each bank.
- more components
- more wiring to run
- less clean set-up (inverter system stays the same so 3 installs vs 1 basically)

Comments please?

 

[RockOn]

Just bumping hopefully for some comments. Thx

 

[400bird]

Why so many separate battery banks?
I understand the backup engine start bank, but not the multiple discreet house banks.

How does power get from the current house banks to your AC panel?

 

[RockOn]

The house banks is the current OEM setup - house 1/port engine and house 2/starboard engine.
Then I have an isolated one for backup start situations.
Each house/start bank is 2 100ah AGM and backup start is 2 1000 MCA crank.

Idea per my diagram is another 2 Lithium 100ah solar bank wired for 24v inverter/battery system that would provide 3000-5000watts through the existing generator 110v via a Gen/Inverter switch. From what I read, 24v better for powering 3000watt inverter and higher. This setup would keep the 24v and 12v systems separate without a stepdown or other equipment.

Current battery bank is through typical rotary master cut-off switches to the 12v portion of the electrical panel (12v house 1 and 12v house 2).
Batteries do not currently interact with the AC portion of the panel.

 

[400bird]

I guess I missed that you had the engine starter batteries listed as house batteries. You really should keep the starting batteries as lead. I don't know what type of engines you've got, but considering it's two batteries per engine, I'd guess large engines. Engines require hundreds of amps to start, well past what most BMSs can handle.

I'd recommend something like system one with the 15 amp battery maintainer to keep the starting batteries topped off. But use hose as starting batteries only.

Run all your house loads and solar into the one large Lifepo4 bank.