VM-3P75CT Gridmeter
3 Fase Multiplus-II 48/5000/70-50 ESS System
30kWh LiFePo Battery Storage with JK BMS.
The Minimum SOC in VM is, intentionally, set to 0%.
GridSetPoint is 0W
16 PV panels with Victron MPPT
House load is on AC in. Nothing conected to AC out 1 or 2.
The setup works very nicely.
It happens once in a while that we actually reach 0% in the early morning, like 07:00 or 08:00 or so.
I noticed that my Multiplusses then start to charge the Battery and even do so if at that moment Solar is already delivering more than the AC Load actually is.
Some where between 5 to 8% they then back off and all goes back to Solar supported Battery charging and houseload.
Of course we can’t keep the Target GridSetPoint 0W as the houseload is there. But charging the Battery is entirely unnessecary as SolarYield wil fill the battery to 100% again during the day. Everything we charge using the Grid we will feedback to the Grid later that day. That’s at least economically undesirable.
My Question that I seem to be unable to find an answer to is, How do I prevent the Multiplus to charge the Battery like that in the ealy morning?
Can you show/tell us the settings you have for the ESS and for the Multiplus?
There is a function, that prevents the battery from staying completely empty, so the Multiplus loads some energy into the battery. I assume, that the distance of your settings is too close from the battery SoC/voltage and that’s why it is recharged.
But going down to 0% seem to be too low anyway? What voltage does the battery reach at this 0% SoC?
Oh, ok. This seem to be all correct. I can only assume, that there is an other value dropping below a threshold. What is the pack voltage when reaching 0% SoC? 16x 2,6V = 41,6V ? What is set up in the Multiplus itself?
Nevertheless, I think going this deep with the SoC is not useful over time.
And just a hint: Maybe you can change the title of this thread, so more community users will be interested and someone will be able to better help you out than me. Something like “Multiplus recharges empty battery unintentional - how to set up”… Maybe this will help.
Oh boy, this is really low. I would NEVER stress my battery so extremely. Is there any reason for that?
I don’t know if in such a case the BMS will force the MP2 to charge from grid. But I would test the DVCC settings: Activate “Limit charge current” and set the value to 0.
Something like “Multiplus recharges empty battery unintentional - how to set up”… Maybe this will help.