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Sailboat Multiplus install

Have a 2001 Beneteau 361 with a Xantrex Freedom 20 and failing batteries. Want to upgrade to 300-400Ah LiFePO4 batteries 12V and a Victron 3000W Multiplus.

Have repurposed one of the Victron diagrams to take a stab at the necessary components. 20201011 Beneteau 361 Electrical Schematic.pdf

Would love feedback.

The shore power is currently two 30A 120V circuits. One powers the Air Conditioning and the other goes to the Xantrex Freedom 20. Planning on having one 50A 120V (three wire) plug and a Victron Galvanic Isolator. The single shore power line would feed to the Multiplus, then split with one circuit to the Air Conditioner (would disconnect if shore power is lost) and the other to the AC panel.

The house battery bank would be 3 or 4 100Ah BattleBorn batteries that have internal BMS. Question: Does the 3000W Multiplus require 400Ah battery bank or is 300Ah okay?

The engine start battery is a FLA connected to a 100 A Balmar alternator with a MC-412 regulator. The alternator would directly charge the engine start battery.

A Renogy 50A DC-DC charger with MPPT would connect to the alternator to provide charging to the LiFePO4 battery bank. Solar is planned in the future and would connect to the Renogy DC-DC charger.

A Cerbo GX with the GX Touch 50 display will be purchased and a BMV 712 battery monitor.

Question: There are 3 switches. Wondering if they are configured correctly. The bilge pump is unswitched, as is the Renogy DC-DC charger.

Question: Did not include a Cyrix Li Charge or a Smart Battery Protect. Are these needed? The Battleborn batteries have a low voltage cutoff in the BMS.

Plan on expanding the system to integrate with a Raymarine or B&G suite, tank sensors, remote management, relays, etc.

Lithium Batterywiring diagram
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2 Answers
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scfoster answered ·

JohnC, thanks so much for the quick response.

Don't disagree with the Renogy box comments. Will add the separate mppt. Planning on two 300W rigid panels at some point (perhaps next year).

I'll get with Battleborn (BB) about the SBP and batt sizing; I agree it's their warranty.

Regarding the switches, thermal breakers and fuses. I "borrowed" the diagram from a Victron posted diagram on the website. So, want to make sure the flow of the wires (switched/un-switched), battery size and components (add mppt) is solidified, before sizing the fuses.

Question: Is there a tool on the Victron site or a recommended external site for fuse and wire sizing?

The reason I'm going with Victron is I'm able to get information, such as what's being provided here.

Thanks again.

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A great general reference is

For fuses, this is indicative of the types Victron supply for systems of this ilk.

Blue Sea Systems are also suppliers of all sorts of quality bits'n'pieces. Worth a look..


Take a hard look too at where you want to be when you're finished. Like eg, you may not need the Cerbo screen if you can access it otherwise. I use a laptop for all things Victron (4 browser tabs & 1 app), and any gizmo I buy needs to be compatible. And that is far from a given with a lot of kit.

So think hard before you open that order book..

JohnC avatar image
JohnC answered ·

Hi @scfoster

Random comments..

With that future glass-bridge expansion, I'd keep the dc/dc separate from the solar mppt. You'll find second-guessing power flows becomes tedious. That Renogy seems to be 25A of each, and frankly, out of place on a Beneteau. Maybe grab a Smart Orion 12/12-30 (or two) and a Victron mppt when you decide on the solar.

You shouldn't need a Cyrix, nor the SBP, but you could ask Battleborn about the latter. Maybe a need for a SBP if you have heavy dc loads? Also ask them about the batt size, they're the ones holding the warranty.

You'll find you can switch the Orion in via it's remote port. Either directly via the engine circuit or maybe with an Assistant in the Multi.

Re the switches, I note you have a couple of thermal breakers either side of the Renogy. I'm not a big fan of them, and would prefer to fuse. You could also use a 4-way switch ex the starter batt to do the same thing as on your diagram (I don't switch my galvanically-isolated Orion on the output side).

Just my opinions. Maybe help kick off a discussion?..

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