Advise needed: dual 12V and 24V house banks or 24V with buck converters

[CaptainRivet]

Hi all,


i am in the conception phase of converting my 12V 840AH installation to 24V.
Reason is i am having big 230V loads resulting in 400-550A draw from the inverters from the 12V house bank. 2nd i could get 4 cells additional from the same batch as mine, so having 16cells now and can go 24V.
Already got 2 units Studer XTM 24-3500W inverter/charger combo which will be 230V with 7kw cont. for 30min, then 6kw forever and 18kw peak power for 5 sec and 2x90A/24 charge. I will use max 5kw continious.


Thinking about having a 24V and 12V LFP house bank (starting from 12V house) in STB hull. Reason is I have plenty of 12V bigger loads, also 12V alternators which with Nordkyn VSR 200 regulators can produce 2x80A charge.

But what is the best way to do this?


I could split my 16x272AH Lishen into 1P8S resulting in a 24V/272AH bank only suppling the inverter but thats a bit tight for 5kw at 24V, close to 1C discharge of the bank. Solar MPPTs charging the 24V bank.

the other have a 2units =banks as 1P4S 12V/272AH 12V house with electrodacus BMS, one locate in STB hull next to 24V bank and other at the Nav-station as buffer battery. they will be charged via 2x115A mitzi=2x80A charge from alternator and 2x50A boost converter controlled by Electrodacus BMS for charge.
Later getting 4 extra cells as 12V house at Nav-station and add the 8x272AH to the existing 24V/272AH bank,

Does this make sense???



Having now:
16 cells LFP 272AH Lishen and 3 electrodacus BMS avaliable


in 24V

only the 2 units Studer XTM 24-3500 using 250A max continious and can deliver 24V/180A via charger


rest is 12V and all new conditions :
2x 12V 115 A Alternators
2x 12V 2000W starter
3x100AH lead starter/house hybrid (toast=dead) in STB and 2x90AH lead starter in BB. COuld move 1 starter 90A to STB, enough for starting the D.-50F.
charging LFP house via 2x Victron Orion DC2DC 12/12/30A

located in the engine rooms STB/BB sugar scoops



rest 12V big draws at Nav station:
12V UC35 watermaker uing up to 12V/50A draw
12V 6x100W class D stereo amp up to 12v/60A draw

12V 1000W anchor whinch (close to Navstation, maybe 1,5m cable), 12V 100A cont, surge/inrush Peak 300A approx
60A old legacy house (Plotter, fridges...) main cable