dirtdiver1977 avatar image
dirtdiver1977 asked

41' Boat Upgrade...Need Advise

My wife and I took the plunge and bought a 1984 Roughwater Trawler for live-aboard (Semi-retirement). It needs a major upgrade when it comes to the electrical side of things that's for sure. So far I have made a list of the upgrades I'd like to make.

MultiPlus II 12/3000

Orion-Tr Smart 12/12-30A (360W) Isolated DC-DC charger

Victron SmartSolar MPPT 150|70

Lynx Distributor

Victron BMV-712 Battery Monitor

Smart Battery Protect 100A

Galvanic Isolator VDI-32

Cerbo GX

GX Touch 50

6x 200W Solar Panels

3x 200Ah AGM Batteries

Now the List that i'm going by currently is from 3000w INVERTER | 400-600Ah | 400 TO 1200W SOLAR-CAMPER by website. I have noticed some wiring diagrams with a battery Isolator and some without when it comes to the Home battery and starter battery. With me using the Isolated Orion do I need to get the battery isolator as well or no?

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3 Answers
jwfrary avatar image
jwfrary answered ·

Common practice on boats is to fit a dc isolator for safety. Also a link for emergencies, back up for engine starting etc.

Curious why your fitting a DC to DC changer when your not using lithium? It would be better to charge via an argo fet diode direct from the main engine or engines, better still using a smart regulator to increase charging efficiency.

Consider lithium batteries, the efficiency gains are worth the expense and they are cheaper in the long run especially for use with inverters.

Also, consider using a lynx shunt and power in as a neat solution rather than the 712 batt monitor

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dirtdiver1977 avatar image dirtdiver1977 commented ·

The Lynx shunt and Power-In are definitely possible as I have thought about using them as well, as I have been watching more and more YouTube videos. My worries are more or less on draining the starter battery (100Ah) as well as the house batteries (600Ah Total) when not on shore power. Currently with the cost of the lithium batteries it's out of reach for us with all that we need to do. The next two years of our "semi-retirement" will be to purchase all the equipment that we need before the install and then actually retiring after and trotting around the Keys and Caribbean. But if it's within the budget ($5.4K) before then I have already looked into Battle Born Batteries to replace the AGM's

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JohnC avatar image
JohnC answered ·

Hi @Dirtdiver1977

Design is your most important challenge. Make a mistake and the kit you've bought may be wasted money. So it's good you've asked.

Head for the Victron website, where there's masses of info. Even example schematics related to the kit you're considering. And in those schematics you might see other kit included and wonder why it's there. There'll be a reason, so then ask if you don't know. This link is general design stuff..

One thing I suggest you reconsider is using a 12V base. I started there and ended up at 48V, much better. Sure I use 12V too, an Orion fixes that.

The beauty of Victron kit is that there's almost always alternatives in the product rrange. This is for practical and personal preferences. Eg. you might choose a Multiplus with a cheaper onboard GX rather than a Cerbo/Touch combo if you prefer laptop/phone/glassbridge access. (also depends on what bells'n'whistles you can do without).

One thing in your list you could probably scratch is the Battery Protect. Useful with serious dc loads, but the Multi can do that for ac, and VRM can be set to alarm on many things.

So keep an open mind. And don't get too absorbed at this stage with choosing isolators/fusing etc. Try to define what you want to do, and how you want to control it.

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dirtdiver1977 avatar image
dirtdiver1977 answered ·


So this is the plan for our Trawler. There is the fridge missing on the A/C But the outlets will be port/starboard sides with 1 gfci on each, small on demand water heater and an a/c unit. the majority of my loads would be dc and have thought about a 12v fridge as well but we'll end up with 80 Qt Bodega fridge/freezer (12v & 120V) combo as well below the galley floor. Only time I really see using the 110v side is on shore power mostly other than the fridge being under way. Have even thought about adding in a a/c selector switch for shore power or a small generator to help with the battery charging if needed when we're on a mooring ball.

600ah-system.jpg (299.0 KiB)
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Victron Offgrid page

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