Hi,
I am re-wiring and rebuilding our ships system. The Multiplus, MPPT, Cerbo, Orions and Argo Fet - as well as the non-Victron Components I have already installed, but I am now switching to Victron NG Batteries and Lynx to have everything in one go.
Attached my wiring diagram. I would love some feedback especially regarding mistakes and things to update.
Here the v1 high-res: High Res Image (v1) - before changes
E.g. in the old system I had a Shunt, but according to all Victron Diagrams that is not present anymore, I expect it to be part of the Victron Lynx BMS NG, but as suggested I added a Shunt for the DC Loads.
It is hard to tell in exact detail because the units and test is so small, but it looks correct at a superficial level.
A couple of comments.
When I installed my NG batteries I swapped the shunt to a DC Energy meter role and put it on the DC loads and set these as the DC system as these are the only unmonitored loads on the system so the Cerbo can log these accurately rather than calculating an estimate. The Lynx NG BMS keeps a good tally of the battery current and SOC.
I believe you have shown a Lynx Distributor for the batteries which has Mega fuses, Mega fuses are not really suitable for the NG batteries which can deliver very high fault currents, >10,000Amps, the fault rating for Mega is something like 2,500Amps (AIC rating). Consider the Class T power in or insert your own class T fuses, or another high AIC rated fuse. I used Blue Sea Class T fuses for my 2 x 12V 300Ah NG install. If AYBC applies then I think they mandate something like Class T.
I currently have a 65Ah Alternator, which is feeding an ArgoFet (200-3), which feeds the bow thruster battery (12V-100Ah), the motor battery (12V 100Ah) and the two Orions (12|12-30) for the house bank (4x 200Ah).
As Victron scales the image down to 1920p (200kb), I have no idea how to show you the original 9000p (2MB) and you cant access imgur.
When I installed my NG batteries I swapped the shunt to a DC Energy meter role and put it on the DC loads and set these as the DC system as these are the only unmonitored loads on the system so the Cerbo can log these accurately rather than calculating an estimate. The Lynx NG BMS keeps a good tally of the battery current and SOC.
I read in different topics here, that the Lynx BMS is far more accurate for measuring the SOC, than the shunt, so there is no need for a Shunt in the system. But thats one of my questions: My main loads (for the house bank) are DC Loads leaving the lynx with two cables (two the 12V switch panel) and the Multiplus (for 220V). The rest is charging (and the Multiplus as well).
…
I believe you have shown a Lynx Distributor for the batteries which has Mega fuses, Mega fuses are not really suitable for the NG batteries which can deliver very high fault currents, >10,000Amps, the fault rating for Mega is something like 2,500Amps (AIC rating). Consider the Class T power in or insert your own class T fuses, or another high AIC rated fuse. I used Blue Sea Class T fuses for my 2 x 12V 300Ah NG install. If AYBC applies then I think they mandate something like Class T.
I havent found a difference on the Victron site between Lynx with Mega and Lynx with Class T fuses, so you would recommend the Two Lynx Class-T instead of the Distributor?
This is Germany, there (I feel) no ruleset applies for sailboats, but that doesnt mean you shouldnt listen and make it right.
If you only have a 65A alternator trying to take 60A from it for many hours to charge the lithium batteries will probably overheat it unless it is designed for full output. Most alternators only want to produce 2/3 of their output continuously, so 45A in your case. With 2 x 30A Orions you may need to turn one off. A better choice would be the Orion XS, this is 50A, it is more efficient and the current can be manually set to less than 50A if the alternator overheats. There is a 70A version just about to be released. I run my 175A alternator at 115A.
Yes the Lynx BMS is accurate. Moving the shunt to the DC load allows the Cerbo GX to take this into account so can make battery charging control by DVCC better, which is why I did it. It only needs to be on the direct 12V loads, not chargers or inverter as these are measured by the equipment and communicated to the Cerbo.
I would always recommend Class T over Mega. There is a standard for Europe, the recreational craft directive and through this ISO 23625:2025 Small craft lithium ion batteries but I have no idea how well enforced this is in Germany. I am in the UK and tried to keep close to this.
I have a new 100Ah Alternator in the spare box, which most likely is going to get installed this year. Thats why there are already two 30A-Orions installed.
Alright, your input reagrding the Shunt is valid, so I would add another Lynx Shunt to the left and let the DC Loads take from there.
And as suggested go with the Class T - I just kept to Victron specs and they suggested two distributors, although one taking the load from the batteries.
No, not a Lynx Shunt, you can not set this to DC Energy Meter mode, ot needs to be a SmartShunt or I think a BMV712 would also manage.
If you are swapping to a 100A alternator then all is good, but do look at the Orion XS especially the 70A version because it is more efficient. It also communicates with the Cerbo fully so it can be controlled by DVCC so no need to wire the remote on off to the BMS.
