For a system (Boat/RV) with no grid code (feeding the grid no allowed), and with that no ESS, I want too realize a (virtual) switch to activate/deactivate the charging trough the Multiplus2. It seems to be impossible.
In node-red I can write my desired setting (e.g. “0” for off and “9999” for max) trough Custom control, but my settings are overwritten fast (most likely DVCC).
I can not/do not want to limit charge trough DVCC as this would negatively affect MPPT/PV charge. What am I missing, was hoping to find a way to simply deactivate/activate the MP2 internal chargers, but this does not seem to be possible either?
In the flow attached you see that I set “0”, but the setting already overwritten with “21”
I did try the “AC Charger Control” node (as can also be seen in the above picture) - it sounds so fitting, but the MP2 is not shown in it’s settings, so I assume this node can only handle dedicated chargers?
What am I missing. Can’t be too complicated to limit/disable grid charge, but still fully utilize MPPT/PV while grid is present?
If you have lithium batteries installed with communications, it is not recommended to ignore the BMS charging limit set by DVCC.
This will prioritise PV charging in any case.
Enable / Disable Ac charging, you can either switch the AC power to the inverter, or you can set ignore AC in on the virtual switch - if you are not using any assistants.
Maybe I was not clear enough. I meant that I have DVCC active, and I will let it do it’s thing (in regards to limits, or whatever the BMS dictates).
I just want a way to limit/deactivate the chargers within the Multiplus, and I want to do this in an elegant/flexible way.
Virtual Switch (ignore AC) trough VeConfig not an option, too unflexible. Want to be able to change how long (down to which SOC) AC is ignored and change such thresholds within the Venus gui (like a slider “maintain min soc" before grid power, value 20-70). I might be able to to that by switching the Multiplus mode from “on” to “inverter only” (manually or with some node-red logic and virtual switches).
Fine, but then, if SOC becomes low (down to a level where I want to maintain a desired minimum SOC), then I switch from “inverter-mode” to “on” (do not ignore Grid anymore) All fine, and this is exactly the time where most of the time I want to limit battery charging from the MP2 chargers (from the grid) down to zero. I will use the grid for my loads as long as it takes PV/MPPT to bring up the batteries to a level where I switch back to inverter (ignore AC) mode. And while connected to the grid, I do wish to prevent (most of the time) the use of grid power to charge the batteries, no need to waste power to transform AC in the chargers to DC and push it in the batteries if there is no rush and the MPPT/PC can do it, while I use the grid for my loads in the meantime.
iirc DC charging will have priority for the charge limit. So if you dynamically adjust that value based on available DC PV then it should throttle the AC-based charging.
I try to follow your suggestion, but so far I can not see how this can work: My thoughts so far (if I understand you correctly):
The DC charging from the MPPT is very flexible in the way of what it delivers (sun, clouds, sun-angle, RAIN, etc) - it basically changes every second, so I never can know what the MPPTs could deliver to dynamically limit my charging rate to that… Is this understanding correct?
Wonder why Victron has (as far as I currently see it) no flexible option to just disable/enable the AC charger in the MP2. I get that setting charge amps manually can potentially cause issues with DVCC (depending on how the software logic is in the background), and therefor DVCC overwrites it as it needs it. But why not just a general on/off possibility (trough node-red or whatever)? I hope I am missing something here, so far it seems so unnecessary complicated.
Most likely best overall solution - if Victron would chime in: Have an option in DVCC to allow/disallow charging from the MP2 DC-chargers - could easily be toggled with some node-red logic, no?
