I have bought a venus Multiplus 48 to charge a battery when there is PV production (and overproduction than my consumption) and discharge my Battery tipically the night.
I was adviced to also buy a Venus GX to be able to control my Multiplus by VE.BUS. I was adviced to use modbus to control the charge/discharge requests (i was forecacting to use python on a raspberry Pi to do the control).
However, i cannot find the registers and how to access to do this control. Can someone help me ?
I attach bellow the desired setup with main informations (i use my own battery and bms with raspberry to obtain SOC and balance the cells of my battery, this part is ok).
I would like to have feedback on the wiring too (i guess i only need to wire AC_OUT for my installation?).
Do note that in youe schematic, it is essential for an ESS system that the battery ESS communicates with the GX device, this is usually a CAN interface, so may be a bit tricky to set up on a Pi.
For the 1st link, this document present ESS function that can be activated inside GX device, but indeed it requires to have battery information to work (ie SOC information of the battery to decide charge or discharge).
In my setup, I want to control the Multiplus behavior (charge the battery from grid) and discharge (inverter only) by writing into the registers of the multiplus.
Do you think it is possible to access the registers of the multiplus (through the Venus GX device) ? if yes , how can i access ?
For example write registers 33-37-38 from âMODBUS-TCP register listâ;
Are you sure that your battery pack is LiIon and not LiFePo? I guess you plan to use a 16s LiIon pack? LiIon isnt that commonly used with these installations, and a 16s may be a bit much for the Multiplus, since the MP is only rated up to 66VDC. Consider using only a 15s LiIon pack
Tension min (Ă 3.275 V/cell) : 16 Ă 3.275 V = 2*26.2 = 52.4 V
Tension max (Ă 4.175 V/cell) : 16 Ă 4.175V = 2*33.4 = 66.4 V
â> so i will control my system, to stay in this range, and i have to check to avoid overdischarge, but i should never go in overcharge because Multiplus will probably stop if violtage is above 66V isnât it ?
Can you confirm ?
could you help me with lines register 2700 and register 2703 : what are the differences betwwen them ?
can i write here values to charge or discharge the battery ?
All galvanic cells operate using the flow of ions. Li-ion is a collective term for all types of lithium-based cells. LiFePO4 cells are one of the many different types of Li-ion cells.
Yep. Looks like we are looking for same, just slight different hardware.
Now, I have nothing. Just read and study all up and down, to be sure I will know what to do after I buy the items.
The list of registers is available on web.. Most likely you have them as you refer to specific data. (I managed to get an excel âCCGX-Modbus-TCP-register-list-3.60.xlsxâ, but canât find the location anymore.)
Are you sure that your PLC is âtalkingâ in same manner with Victron?
For instance, when reading my energy meter, in order for Arduino to understand it, I had to revert / flip the signal to make it work, even my NMEA/USB cable did work directly. So, you may say correct, but just upside down.
Use a serial terminal to send commands to Victron and see what is doing. If that works, then you are on correct address. And etc. you know how to take it from here.
I have no clue if what I say is correct. Just thinking out of the box.
Yes iâm sure, because i use Modbuq protocol (on ethernet ) that is more âelaboratedâ than serial link: and moreover i read perfectly the DC voltage on Modbus (with 0.1V resolution as described in the modbus description), so no flip or such staff to do.
what metering are you using ?
Registre 800 : 12336
Scan des registres Modbus TCP sur venus.local unit-id 242âŠ
