The other day I replaced the GX device in my MPII with a dedicated Cerbo GX.
Everything is up and running and re-configured, but I have one issue I cannot solve… I suspect its an option / configuration somewhere but I can’t find it anywhere!
System Configuration:
All loads are on AC Out ‘Critical Loads’ of MPII GX 48/5000.
Energy meter ET112 on the incoming grid supply.
SolarEdge PV on AC Out ‘Critical Loads’.
Dedicated Cerbo GX replaced MPII GX from 4th Oct.
400Ah Pylontech (4 * US5000) on VE.Can 2 of Cerbo GX (configured as CAN Bus BMS LV).
Prior to the update (3rd Oct 2024):
VRM Consumption: Shows ‘From Grid’ value aligning to the grid supplying the house base load during battery charging.
VRM Grid: To Battery is the majority of the import and the base load is identified correctly as ‘Direct Use’ whilst the Import Schedule is in force.
Since the Update (Today as an example):
VRM Consumption: Shows a much higher ‘From Grid’ value which appears to be consumption that is charging the battery.
VRM Grid: The energy to charge the battery is appearing primarily as ‘Direct Use’ rather than ‘To Battery’. I have no other loads other than house base load at the time.
See the following image of describing the issue pictorially:
Can anyone shed any light as to what configuration would cause that Pylontech batteries charging from the grid to appear as ‘Direct Use’ rather than ‘To Battery’?
can you check betavrm.victronenergy.com (You can just login with your normal credentials) - there is a refreshed view of this graphs that will soon ™ be released, which is more detailed on telling the energy flows apart. See also:
Edit: Ah, you are referring to the “System Overview Graph” - well, that is something else. But you could check the beta, if these values have been adjusted as well with the changes on DESS outlined above.
Don’t mix “Consumption” and “From Grid” they are obviously not the same thing. Energy that is flowing from the grid to the battery obviously is “from grid”, but not (yet) “consumption”.
Grid to Battery: Makes sense - Scheduled charging is in effect.
Grid to Consumption: Low background use of Grid to support / sustain house base load whilst batteries charge.
Today
Grid to Battery: Initially very low 01:00 - 02:00 and lower than expected at 02:00 - 03:00.
Grid to Consumption: Far higher than expected! There is only the house base load running. This should mirror similar to 3rd Oct 24 but does not. That is unless, for whatever reason the system is classifying energy into the battery from the grid (what should be ‘Grid to Battery’) as ‘Grid to Consumption’ incorrectly.
Below you can see the Battery Power, System Grid and Battery Charge level during the scheduled charge. As soon as the battery hits 85% it returns to just base load being satisfied by the grid.
To note I tried ‘Keep Batteries Charged’ mode to see its affect. It’s what I would expect:
Grid: ‘To Battery’
Consumption: From Grid minimal. I.e. no sign of consumption being registered during the battery forced charge.
Around 9am I opened up the MPII GX and disconnected the power and Ethernet for it’s embedded GX device. I’ll await tonight to see if that makes any different. Not sure why it would because other than a VE.Bus connection (to the new Cerbo GX) there are not communication connections.
Problem solved. I suspect it was the GX device within the MPII that was still internally connected that was causing the issue. Now it’s disconnected the grid and consumption overviews make perfect sense again!
