I have tried a multitude of settings but with no luck. Currently I have set the following:
ESS assistant on optimised without battery life.
Multiplus II set to inverter only not charger ( This is intentional as we don’t want the grid to charge the batteries but simply take over when the batteries run out).
I set a gridpoint level to 200w ( hoping to keep some load on the grid as a test manily)
The SOC is set to 23%
AC input in the multiplus II themselves is set to accept a wide voltage.
I have added some screenshots below of the configs and also some screenshots showing that although AC is identified on the AC-in ( voltage and frequency showing) it seems to be ignoring it as it doesn’t show on the GX dashboard and the batteries have already gone past the SOC point set (23%). I have tried changing AC input to generator instead of grid but still no luck.
I am hoping someone might have had this experience and can assisit. Thanks in advance!
Hi Nick, yes correct so naively I thought by having it on inverter only it would not affect the fact that it would ignore the Grid. So i turned it back to “on”. However I remember why I did this and it was because even though I set to use ESS without battery life … the grid was still attempting to charge the batteries. This led to very unstable behaviour as the PV’s stopped producing as you can see in this screenshot with battery % still at a healthy 70 - 80 %. It was varying so much we had to cut the supply and go back directly to grid… you can see the moment where loads go to 0.
For example with the batteries full and solar available it still fluctates and pulls from the grid. Impossible to leave the multiplus II on, having to put it in inverter only to stop the pulsing. In this isntance i set a limit on the grid at 2A to test and it completely disregards it and continues drawing more than those 2A from the grid.
Your system is in passthrough, that will cause the behaviour. That can only be an installation or config issue. common passthru issues are documented in the ESS FAQ’s.
well it isn’t always … that’s the thing, it’s not very predictable. Here it is in another mode, but constantly jumping between -150 and about 250w .. these are low values sure but still seems weird
Do you have a grid meter?
If so, loss of comms will trigger passthru.
The setpoint fluctuating is quite normal for an ESS, how much it does will depend on a few factors from the system size (multiple inverters, parallel etc) to loads.
from the FAQ:
In ESS, the conditions for the VE.Bus system to be in pass-through (ve.bus state: passthru) are:
When the GX device is no longer receiving data from the grid meter. Note that this is only for systems that are configured to have an external grid meter. See the Settings → ESS → Control without grid-meter setting.
Systems with a canbus-connected lithium system: when the GX device is no longer receiving information from the battery, via the CAN-bus.
When charging the battery is not allowed (BMS max charge current = 0A, or max charge power = 0W) and there is excess PV power.
When discharge is not allowed -and- loads on AC-Out force the Multi/Quattro to exceed the AC input current limit. Reasons for not allowing discharge: BMS blocks discharge (DCL=0), or battery SoC level is below the ‘minimum SOC’ setting in ESS, when SoC is at least 3% above the set level, discharge is allowed again.
A grid code is in use that requires the enabling of battery discharging by aux-inputs. Check the used grid-code in VEConfigure and compare with the electrical signals provided to the Inverter/charger in its AUX inputs.
LOM on some connections can be a problem. It is easy enough to test but please be aware of what local regulations require as turning it off may not be compliant.
