New battery/inverter-charger/solar setup questions for a sailboat


Solar Addict
Feb 11, 2021
There are many ways to do this. There is no one size fits all schematic Break it into small parts. Start with the alternator. What battery will it charge? Draw out just the alternator and its battery. Now add the dcdc charger. Etc.

If you are not familiar with this, you NEED to do some reading on marine electrical. There are considerations unique to a boat and some rules to follow.

But to get started, sketch out what you have bit by bit. Don't forget fuses and wire sizes. Post here for feedback.

I agree, victron drawings are often difficult to follow.

Regarding the DCDC and alternator. It really depends on the quality of alternator and regulator. External is better than internal, but either might or might not be able to handle charging LFP directly. If the alternator can not, then connect the alternator to the lead battery, and use the dcdc to charge the lfp. This is safest, but drastically slows charging of the LFP.

If the alternator will safely charge the lfp, then you can omit the dcdc charger and use a simple charge relay, battery isolator, in a dozen different configurations. But this usually requires an expensive alternator and a wakespeed or balmar regulator. It allows charging at very high rates, maxing out the alternator potential.

I have a BMV-712, and get less than 10 feet. Its the environment, not that the smart shunt has more or less range. Bluetooth shares spectrum with 2.4GHz wifi. A crowded area or misbehaving wifi device will affect Bluetooth reliability. It my laptop connects to a 2.4GHz hotspot my Bluetooth mouse doesn't even work. But if i use 5GHz, everything works fine.

AK Sailor

New Member
Feb 27, 2022
As components are now arriving,
I’m in the process of upgrading the system on my sailboat and a little overwhelmed by the complexity of most of the schematics from Victron. Can’t seem to find one that closely resembles what I’m trying to do.

-1 lead acid start battery

-100 amp internally regulated alternator

-Orion 12-12 30 amp isolated DC-DC charger

-2 206Ah Lithium batteries w/ integrated BMS (these are still stuck on a container ship!)

-1 Multiplus 3000 12v inverter charger

-2 Victron MPPT charge controllers to be added (planning two arrays totally approx. 600 watts)

-Cerbo GX

-Victron Smart shunt (500Amp)

-Both AC and DC

Can someone point me in the right direction in terms of an appropriate schematic?
Thanks in advance!
Did you ever find a schematic? I am just now looking at doing the same system layout in my boat.


New Member
Nov 21, 2021
Did you ever find a schematic? I am just now looking at doing the same system layout in my boat.
I never did find a schematic that perfectly matched my intended setup. The main lesson I learned from feedback and research is that the shunt is placed directly after the Neg coming off the batteries and the class T fuse is placed directly after the Pos coming off the batteries. After that, the rest is fairly simple. I’m mostly finished now with the exception of adding solar. I added a 30 amp Dc-Dc which is working great with my stock alternator. If I was doing it over, I’d consider using a Lynx distributor to consolidate things. I just noticed that the latest video from Will Prowse covers Victron components. I’m very happy with all of the Victron stuff I have, especially the CerboGX and the Touch display. Love the visual representation of what’s happening in real time.

Another user shared this photo which is somewhat similar to my system. In it, you’ll see he used the Lynx distributor. No Dc-Dc either, but otherwise a good setup for a boat.

Good luck!


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