Victron DVCC share voltage doesn't work with my 3 victron 50/100 MPPTs

[CaptainRivet]

Hi all,

DVCC voltage sense share doesn't work with my 3 MPPT 50/100

I have a system installed in my boat that consists of 1 Multi, 3x 50/100MPPT, BMV712 on the lithium battery, all connected to a cerbo GX and with an electrodacus BMS that's not connected to cerbo. All show up in the device list of cerbo and updated to newest firmware, the BMV712 is correctly connected and configured as battery monitor in system setup of cerbo after I finally got my rj12 cable now 2.5month after ordering it.

Ve.Smart BT link is off, so this doesn't interfere.

DVCC is on and voltage sense share on too. BMS control off or automatic, shows none (tried both)

Due to mvader and manual dvcc with voltage sense share still works but it doesn't.

my system overview shows:

use solar charger current to impove SOC: ON

Shared voltage sense : OFF

Due to manual the voltage sense also works when no BMS is in control.

My issue that the 3x 50/100MPPT only have one VE-direct port and connect that to cerbo to get data for monitoring but I also need to cut all 3 off with a battery protect when lithium is full. This was recommended by mvader to me, you can also find this setup on a victron reference diagramm. The issue with the MPPT (2x are Smart BT but one not)if cut off with BP the MPPT don't see the battery voltage and go haywire and rise voltage till BP220 goes with 16V into overvoltage protection and BMS cannot connect them again. This problem should be solved by using DVCC with shared voltage sense as they get the voltage this way.
Well voltage share doesn't work.
I had this sorted till now (because the rj12 cable was missing to connect shunt to BMV712 ) by sync voltage of the 2 smart MPPT via ve.smart BT and the 3rd non smart MPPT was not connected to cerbo and cut off via the VE-direct adapter cable.
Now after getting the rj12 cable and BMV712 battery data in cerbo I wanted now all 3 MPPT as originally planed connected and sync via voltage shared as advised by mvader.
What's the issue here? What did I miss?
Posted on victron forum too but no answer, maybe somebody knows here what's wrong...jedi?

[rslifkin]

Check the DVCC settings on the Cerbo. There should be an option to manually choose the voltage sense source if it's not figuring things out well enough in automatic selection.

[CaptainRivet]

Originally Posted by rslifkin

Check the DVCC settings on the Cerbo. There should be an option to manually choose the voltage sense source if it's not figuring things out well enough in automatic selection.

In which submenu do I find that?
In DVCC I have only DVCC on, manually turned on shared sense voltage and shared current sense, shared current sense is active.
BMS controll: can only chose BMS control between automatic and no control.
Nowhere possibility here to select voltage sense source

[rslifkin]

Originally Posted by CaptainRivet

In which submenu do I find that?
In DVCC I have only DVCC on, manually turned on shared sense voltage and shared current sense, shared current sense is active.
BMS controll: can only chose BMS control between automatic and no control.
Nowhere possibility here to select voltage sense source

I'm not on the boat right now so I can't look at mine, but on my system with a touchscreen connected to the Cerbo, under Settings, DVCC there are options to change the source for shared voltage sense and shared current sense. It might require having the user mode set to "superuser" to see those settings.

[CaptainRivet]

Originally Posted by rslifkin

I'm not on the boat right now so I can't look at mine, but on my system with a touchscreen connected to the Cerbo, under Settings, DVCC there are options to change the source for shared voltage sense and shared current sense. It might require having the user mode set to "superuser" to see those settings.

I am in superuser, have victron large and gui mods. Have no touch screen use remote console via tablet.should be the same.

[rslifkin]

Originally Posted by CaptainRivet

I am in superuser, have victron large and gui mods. Have no touch screen use remote console via tablet.should be the same.

I think I found what we're missing. It looks like when the Cerbo is talking to a BMS it hides the option to choose the voltage, current, and temperature sources (my setup still has lead batteries for now, so it shows these).

The good news is, it should be taking the voltage sense from the BMS. So that shouldn't be your issue, it's likely something else. Possibly a behavior issue with the MPPTs where they just can't regulate voltage properly if the battery side is totally disconnected, although I can't confirm that suspicion.

[wholybee]

Have your tried BT? My system is quite different form yours, but the MPPTs connect to the BMV-712 via Bluetooth, and the (I forget where as I'm not on the boat) MPPT and BMV will both report that the connection is working and the MPPT will show they are using the BMV.

I can otherwise only guess the MPPTs need to be connected to the battery. I sort of would not expect it to work properly without supply voltage from the battery.

[s/v Jedi]

If you want to remotely switch mppt controllers on/off you must buy the models that have a remote on/off port.

When you connect a CanBus BMS to the Cerbo, you give that BMS full control over everything. Every error leads back to the BMS.

[CaptainRivet]

Originally Posted by s/v Jedi

If you want to remotely switch mppt controllers on/off you must buy the models that have a remote on/off port.

When you connect a CanBus BMS to the Cerbo, you give that BMS full control over everything. Every error leads back to the BMS.

I have non of these and not plan to make private equity victron richer...2nd the 50/100 fit perfect one MPPT per 700W bifacial panel to get most out of one panel. Non of the more expensive remote port ones fit as too small or too big and I spent already 900 Euro for 3 products with a major design flaw...
You can switch them directly on/off via the ve-direct to remote cable and that's how I had them before switched on/off by electrodacus. And in case it's not working what victron suggested I simply go back to what I had and put a smartshunt into negative cable of the chargebus and get the solar data this way into cerbo...much cheaper or replace that non smart with a smart and do charge sync via BT Ve.Smart.

To be able to get them and whole system on cerbo mvader from victron suggested the following:
Electrodacus BMS doesn't talk to cerbo as its not yet integrated via the serialbusdriver. A BMV712 is connected to negative terminal of the bank and delivering current, voltage and SOC to cerbo instead Electrodacus.
The Electrodacus BMS switches the 3 MPPTs (actually the whole chargebus but the MPPT are the only issue here) by interrupting the charge side via BP220, the same way victron does via the Victron Smart BMS also shown in the reference install diagramm for it and recommended to me by Mvader.
This way the ve-direct port is free to connect to cerbo, report all data and gets via DVCC the sense voltage share from the BMV712. That sense voltage share is necessary so the 3 MPPT get the real battery voltage when cut off by the BP220 as they don't see it anymore and go haywire raising voltage. Cannot use BT victron smart as one of the 3 MPPT is not smart one and one of 3 is enough the voltage raises to >16V and BP 220 goes in overvoltage protection.
But again DVCC should solve this issue but doesn't.
Manual 8.4 DVCC also states voltage sense share works with or without BMS or ESS and is independent from battery type...

Jedi and this DVCC voltage sense share doesn't work, the question is why and how to fix it? This was my question and nothing else.

[smac999]

Originally Posted by CaptainRivet

my system overview shows:

use solar charger current to impove SOC: ON

Shared voltage sense : OFF

The top one is if using the multi as a battery monitor. (Only measuring multi loads) it will add mppt loads to multi loads. On a boat this does not work because of all the other loads. So in the multi settings. Using the multi for Soc should be off. At which point that setting will probably not exist. You are not using the multi for Soc. You are using the bvm.

Your post is about shared voltage sense not working. Well you have it off. So turn it on.

[CaptainRivet]

Originally Posted by smac999

The top one is if using the multi as a battery monitor. (Only measuring multi loads) it will add mppt loads to multi loads. On a boat this does not work because of all the other loads. So in the multi settings. Using the multi for Soc should be off. At which point that setting will probably not exist. You are not using the multi for Soc. You are using the bvm.

Your post is about shared voltage sense not working. Well you have it off. So turn it on.

DVCC is on as well as shared voltage sense and shared current sense which shows active.
In system setting the BMV712 is set as battery monitor also for SOC.
Just checked multi battery monitor is off, SOC show "--" in the cerbo SOC setting in the multi menu
The MPPTs are connected and see with some voltage loss due to cables and fuses the battery voltage and system overview states voltage sense share and current sense share is off...
Also rebooted cerbo, the same...
So where is the issue here?

[rslifkin]

When the MPPTs are operating, do they report the voltage you'd expect for shared sense or do they report their own voltage?

[CaptainRivet]

Originally Posted by rslifkin

When the MPPTs are operating, do they report the voltage you'd expect for shared sense or do they report their own voltage?

They report their own voltage...that's how I see its not working as well as if I go to mppt in device list into network: networking No and network status standalone

[wholybee]

Originally Posted by CaptainRivet

They report their own voltage...that's how I see its not working as well as if I go to mppt in device list into network: networking No and network status standalone

If you set them up with the Bluetooth, they will report the voltage from the BMV-712. That might solve your issue, at least for the 2 smart controllers.

I often suggest the simpler approach. I fail to understand why the need for the BP to stop charging via whatever is controlling it, instead of letting the MPPT do its job. I have never bought into the need for a BMS to control anything other than shutting down an alternator before an HVC. It seems like your problems stem from making everything overly complex.

[CaptainRivet]

Originally Posted by wholybee

If you set them up with the Bluetooth, they will report the voltage from the BMV-712. That might solve your issue, at least for the 2 smart controllers.

I often suggest the simpler approach. I fail to understand why the need for the BP to stop charging via whatever is controlling it, instead of letting the MPPT do its job. I have never bought into the need for a BMS to control anything other than shutting down an alternator before an HVC. It seems like your problems stem from making everything overly complex.

The Electrodacus controls everything like a victron cerbo does if you do DVCC with BMS controlling but much simpler and on cell level. Why let an mppt control that has no glue about cell voltage and SOC...
I just want cerbo monitoring and to get all 3 MPPT into cerbo instead switching each of them I use a BP220 to switch them all at once to have the ve-direct free.
DVCC is marketed to be super simple, you just connect and give control...reality again is different as with many things with victron... I am sure just somewhere tick a checkbox is missing or I have to enable somewhere something...but what.