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navoye asked

DVCC not working?

Hi, I build a system: BMV-712 as battery monitor, SmartShunt as DC meter and SmartSolar MPPT 150/45 (all on newst firmwares) connected to 24V battery and 820Wp PV. Off grid. I add rpi with VenusOS (v3.01) to get DVCC but it doesn't work. On SmartSolar i set charge limit to 30A by Victron Connect, in Venus Os i enabled dvcc with charge limit set to 13A(I use lead acid). Limit work's fine, battery charging never goes above 13A but dvcc does not take into account the current consumption from the DC metter and does not incrase production - it just holds the current limit at a fixed position. This is not how it should work - am i right? A constant charging limit can be set in SmartSolar without VenusOS... Or is something missing in my system to make it work? I've read everything i found, I don't see why it doesn't work. Can somebody help?


forgot to add: everything is connected via usb to VE.direct and conections status is ok, all visible from VenusOS. There is no VE. Smart network set and never been.

Raspberry PiDVCCVenus OS v3.00-32
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Alexandra avatar image
Alexandra answered ·

@navoye

Leave ithe mppt at the 45A it can do, dont limit it. Your panels wont get you there anyway. (820w ÷ 24v is 34A) (÷ 26v even less...)

Which shunt is set up as the battery monitor for the system, is there a problem there?

Do you have has DC system enabled?

It is also possible that the solar isn't producing because irradiance or atmosphere conditions are weird. Speculation here ...

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navoye answered ·

I will set up mppt at the 45A for tommorow, i know that panels wont get there that's why i set it at 30 but will see what will change if i change it to 45A.

As battery monitor for system is set shunt connected to BMV-712 and its set in venus. I also try as "automatic" with no effects. I got all the readings fine.. SOC, DC meter etc. Only DVCC dont get it and do what it should do.

Has DC system is enabled ofcourse - i forgot to write it.

I was thinking about solar producing but.... We got full sun and everyday max is equal 13A - its almost not possible... but i have a plan to check it tommorow. I'll put big load for DC and then increase dvcc limit. If it will go up then there will be 100% certainty that it's not the fault of the panels or the weather.

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navoye answered ·

So after a lot of testing I think I've found, maybe it's a simple bug. When I was configuring the shunt as a DC meter, I chose the type as "inverter". I've done a lot of testing in full sun. I'm 100% sure DVCC wasn't working as it should. It only limited MPPT power, without adding DC meter information. Yesterday I played around with the setup again and decided to select the type as "DC system". Now it works as it should. I checked again and found no information in the manuals that DVCC to compensate for current from a DC meter requires the selected type as "DC system". Like I said, maybe it's a bug. But now it works and I'm happy. Maybe this information will be useful to someone in the future.

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seb71 answered ·

Hi, I build a system: BMV-712 as battery monitor, SmartShunt as DC meter and SmartSolar MPPT 150/45 (all on newst firmwares) connected to 24V battery and 820Wp PV. Off grid. I add rpi with VenusOS (v3.01) to get DVCC but it doesn't work.

You did not say what is connected to the SmartShunt.

A non-Victron inverter?

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navoye avatar image navoye commented ·

I don't have a Victron inverter, the entire system load is 24V connected to the DC meter. I emphasize once again that the entire system is OFF-GRID. I usually take 24V for lights/pump. Sometimes I also connect 24V-->230V converters(by the same DC meter). However, it is still just a normal 24V load that is measured by a DC meter and measured correctly as indicated. In the DVCC requirements I did not find information that there must be an inverter in the system. Is it so? It would be good to clarify this case because I've seen other people's posts with similars problems. Some of them find a way by doing it by Nod-red to get it working......

And I still don't understand - DC meter is DC meter - it should be included by DVCC no matter what type you choose.....

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navoye answered ·

Yes, its set in GX, and everything shows right. in VRM also.

I don't think you're going wrong way. You are looking for equipment not Victron and problem there. From an electrical point of view, a 24V load is a load. Since Shunt measures them correctly, it shouldn't be a problem whether it's an inverter, light bulb, fridge or whatever. It's still just a 24V load.

The question is different and worth focusing on for others:

Why when we set the shunt as "DC meter" and choose anything other in type than "DC system" then DVCC does not work properly. And when we choose the type as "DC system" they work. According to the instructions for load compensation via DVCC only the setting shunt as "DC meter" is required. The types that are available are only mentioned, but there is no mention that any specific one is required. I don't know how it is on the Victron Cerbo. Maybe it's a bug only in Venus for Rpi, or maybe it's supposed to be like that, I just haven't found any information about it.

As I mentioned - for me now everything works as it should and I'm happy. There is no problem for me.

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navoye answered ·

I don't know how it works in Cerbo, I wanted to buy it after testing on Rpi, but I'll hold off for now... too much ambiguity. Anyway, further observations apply to the behavior in VRM:
1. When the shunt is set as DC meter and the "DC system" type is selected, DVCC takes into account the current consumption measured by it, VRM in "Devices" displays it as "DC system", in the advanced tab there is NO WAY to display widgets from it - just not displays in the list. Restarts, deleting, adding, reseting, nothing.
2. When the shunt is set as DC meter and I choose a type OTHER than "DC system" DVCC does NOT take into account the measured current consumption, VRM in "Devices" displays it as "DC load", in the advanced tab it appears immediately with widgets as "DC load".

The "DC system" type must therefore be treated in a special way. It is a pity that it is not described in the documentation, it is written that it is enough to set the shunt as "DC meter". I am very curious how it behaves on the Victron Cerbo. Is it a documentation error or a bug in Venus for Rpi? Mayby someone will test it. Currently I leave it as it is(type "DC system"), I can manage without the graph, DVCC works. I'm happy.



This will be the last update - despite the situation described in point 1, you can enter the "custom widget" and there the "DC system" is visible, you can create a graph as you like and it works. It's all weird...

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seb71 avatar image seb71 commented ·

From the SmartShunt manual:

https://www.victronenergy.com/media/pg/SmartShunt/en/all-features-and-settings.html#UUID-a8b42cd2-2e6d-c938-d60c-4ae2beea0e0a


7.4.3. Monitor Mode

If you wish to use the battery monitor to monitor individual DC circuits rather than as a whole-of-system battery monitor, you can change the "Monitor mode" setting in the "Misc" menu from "Battery Monitor" to "DC Energy Meter".



If "DC meter" is selected, you can select the following types:



Solar charger, Wind charger, Shaft generator, Alternator, Fuel cell, Water generator, DC-DC charger, AC charger, Generic source, Generic load, Electric drive, Fridge, Water pump, Bilge pump, DC system, Inverter, Water heater.



When connected to a GX device, the type, the current and the power is shown in the user interface, and this information is also available on the VRM Portal.



When the GX device is also configured as type “has DC System”, the GX does more than just recording and visualisation:



  1. The power shown in the DC system box is the sum of power reported by all battery monitors configured as such. Having multiple meters can be useful, for example, in a catamaran, so that the DC systems in the port hull and in the starboard hull are being measured.

  2. The DC system current is being compensated for when setting DVCC charge current limits to inverter/chargers and solar chargers. For example, when a load of 50A is being measured, and CCL by the battery is 25A, the limit given to the inverter/charger or solar charger is 75A.



See the GX device documentation for more information about these advanced features, especially refer to the Distributed voltage and current control chapter.



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navoye avatar image navoye seb71 commented ·

All in all, after the experiments I have done, I agree - it is described in the manual. It's a pity that no one paid more attention to accurately describe such an important function. I still don't understand why other loads are not compensated... but that's how it's works and that's it. A big reward for those who having no hardware in their hands or training with only this manual will be able to tell how it works ... However, I still can't see an explanation why the VRM can't see the DC system normally. Doesn't matter.
Let's leave it. As I mentioned I already know what and how. I achieved what I wanted. I hope my detailed description above will help others looking - I've seen posts asking the same things of DVCC, I've seen posts from people with no DC system in VRM. I'm not the only one, maybe it will help someone. As you can see, the help on the forum was also not clear and people didn't know where to look and were asking about lot of other things. After these experience my first question to someone who has this problem would be "what type of DC meter is selected in shunt". Problem solved right away....

regards

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