Are there any plans to be able to set the Multiplus-II's battery charge current in Venus OS?
asked
Multiplus-II charger current setting in Venus OS
This can be done at the moment by BMS systems, So could be done by a script?
Why do you need to set the Battery current (or the AC input current)?
@Mike Dorsett The grid is very bad in my country and we have several power outages a day. I would like to be able to adjust the Multiplus-II battery charge current from Venus OS to charge the batteries from the grid when it is over cast or at night once the grid returns to ensure power for the next day.
At the moment I have to unplug the VE direct to USB cable from the Raspberry Pi and plug it into my PC to change the setting on VE configure.
This is the setting I would like to be able to set from Venus OS:
(image merely an example found online - not my actual settings)
I currently keep the charge current set to 5A in case I need to run heavy loads and dont have enough PV available and dont want to abuse the batteries.
In such a case I set ESS to 'keep batteries charged' and run the heavy loads solely off of the grid.
I found one document on-line: com_victronenergy_battery_dbus_spec.txt
This gives (amongst others):
DVCC & BOL related paths. These are published by batteries.
/Info/MaxChargeCurrent <- Charge Current Limit aka CCL (BYD, Lynx BMS and FreedomWon)
/Info/MaxDischargeCurrent <- Discharge Current Limit aka DCL (BYD, Lynx BMS and FreedomWon)
These are the DBUS service requests that set the charge /discharge parameters once DVCC is enabled in Venus.
As the Pi doesn't have an analogue input, and the Venus Os appears to be a display only process, you would need to write a service that read an input pin from the Pi, (or several if you want a variable control) and used this to control the current by issuing the Dbus service request. These probably need to be issued periodically (BMS send them every scan), so as the DVCC thinks it still has a BMS attached. Not sure how this would react with an ESS control system as I haven't used that. Hope this helps.
DVCC allows setting a system-wide max charging current. That would be easy to change with a script writing to the dbus parameter.
