Hi there
I have an ESS with Multiplus II, Cerbo GX, Shunt and 4 x PylonTech (5000) Batteries.
in VRM both Battery Charge Energy (kWh) & Battery Discharge Energy (kWh) show No Data to Display. I have selected Charge Energy from the Shunt and Discharge Energy from the Pylontech BMS just to rule our one or the other. Both show No Data
The same issue in Home Assistant for the same data.
I have searched for info on this problem on the forum but haven't found anything
You help would be appreciated !
I think those metrics only exist if the bms sends them which none seem to do.
There are quite a few available metrics which can’t be charted.
I will have to find out how to get HA to convert W to kWh. If you have any expertise in this area I am all ears !
Thanks Nick
What would be the best way to calculate Battery Charge Energy (kWh) & Battery Discharge Energy (kWh), as a daily figure?
I'm using Node Red, you can select these outputs for the Lynx Shunt, but there is no actual values.
Edit:
I already calculate battery watts, so I added a switch node, which directs the flow depending on if the value is positive or negative, this then passes through a function which contains the following if positive.
//Calculate time since last reading taken - usually around 5 seconds
var d=new Date();
var duration = ((d-flow.get("LastTime"))/1000)
flow.set("LastTime",d);
//Calcualte kWh used during the last duration period
var kWh_Day = flow.get("Bat_kWh_Charged"); //Bat_kWh_Charged is reset to 0 at midnight
var BatteryWatts = msg.payload;
var kW5s = BatteryWatts * 0.001 / (3600/duration);
//add it to the daily total
kWh_day = kWh_Day + kW5s;
flow.set("Bat_kWh_Charged",kWh_day);
msg.payload = kWh_Day;
return msg;
The other function is the same, but the context variable is Bat_kWh_Discharged, the two context variables are reset at midnight. Last time is intitiated to the current time if the system is rebooted.
Hello,
I wrote a python script to be run on the CerboGX to calculate charge and discharge energy in kWh and inject then on the dbus: data are available in VRM.
I testes them with my one battery US5000 bank and get a 97% efficiency.
Script is available here on github
Regards,
Benoit
