Originally Posted by AllenRbrts
I question the value of 5 solar controllers. The panels can be in parallel and shading will not effect the other panels. Seems like lots of wiring and hardware
with little gain. I run 3 panels on one controller, works great. If much of this is a new install have you thought about have the core
of the system at 24v? Lot smaller wire sizes.
I am starting my LifePo4
install in my FP Lavezzi
40ft cat too
12V vs 24V: normally 24V but
I am in the same situation then you, new engines with new 12v alternators and starters, new overhauled 12V windlass
and a quite new 12V watermaker….
Well it’s cheaper to stay 12V and have bigger cables
directly from the 12V 5kw inverter
to the LifePo4
and don‘t go on the main bus for that. So I can keep main positive bus to 150A continuous (all is speced for 300A) and the Max. 400A load from inverter
goes straight to house LifePo4 with its own fuse.
Like this you don‘t have to size your main busbars that massive and as everything else has smaller fuses
I use Electrodacus BMS and this has 2 shunts directly on the positive pole of the battery
to measure what’s going in and out as no current
flows through this BMS.
So on the 750A load side shunt I connect 3 fuses
type NH3, one 300A for the main positive load Busbar and two 250A, one for each of the two 120mm2 cables
to the inverter. Like this you stay below the common 300A continuous rating and things don‘t get hot. Highly recommend to use only NH3 fuses as main fuse, the mega fuse „toys“ melt away or create a lot heat problems with continuous loads above 150A….yes they have rated fuses till 400A
5 MPPT and bifacials:
Perfect choice bifacials, due to diffusion light they are much less prone to shading…on passage
I have now 80% of my charge amps on anker.
My experience right thing to do with bifacial panels. Yes more effort for cabling but worth it. You get 2x6mm2 in one cable and this is easy to route
, so 5 of them.
First Victron has only 85A and 150A MPPT, so 2 or 3 panels on one controller. Using 2 440W bifacial on the 85A MPPT will max it out quite frequently so life is shorter, 2nd cable getting quite big if you go to 150A version. Costs: you not saving much. 2nd if one controller breaks you loose 2-3panels, 880 or 1320W..oouch
More important 1 MPPT per panel can track much better as bifacials profit from more tracking then normal panels. I also have Victron MPPTs.
Have 3 panels Longli bifacial 365W (only front speced, backside delivers up to 25% additional
) on 1 MPPT with 2 panels parallel delivered Max 790W and 1 panel on 1 MPPT which delivered 440-460W, means total 790+460=1250W. now having 3 MPPT on 3 panels so each on one MPPT I now see 440-460 from each of the 3 panels, means 3x460W=1380W. All 3 panels over the davits
, only exchanged the 1 85A Controller to 2 x 50A and run an additional cable with 2x6mm2 to the 3rd MPPT, nothing else changed.
What’s that switch on the DC to Dc charger
The Orion has a remote
switch so you don‘t need a high current
switch to interrupt charging
manually, just switch it of via remote
means put a switch via remote.
Like your wiring on the starter battery
is set up now, if your BB starter dies you cannot switch over to the STB one.
I would put a combiner in if one engine
, so 1 alternator
is running the combiner connects both it is charging both starter BB and STB. That’s how it’s normally set up already with lead batteries
in cats. 1 hull
is normally starter+house, the other is only starter and when you run one engine both sides will be combined. You can keep it like this and just put both DC-to-DC charger
in parallel on the Hull
side where your old house+starter was/is and thats most like where your new LifePo4 will be installed too, typically BB. So if you run one engine both DC-to-DC charger will charge=60A, your 125A one can handle this. If you run the STB engine the Batterie combiner will combine both starter bat and the 2 DC-to-DC starter will start charging too. If you run both engines the same but the charge load is shared.