The following configuration exists:
Multiplus 2 GX used as an UPS system, with a managed battery.
No assistants are used.
DVCC is not used, but the BMS is reporting the precise SOC.
Normal image (non large), so no Node-Red availability.
Instead, the virtual switch is used as “dedicated ignore AC input” with the below configuration, in order to cycle the battery and not keep it long periods at full charge:
The system charges the battery and after the set absorption period ends, it disconnects the AC-IN.
Then, the system works only on battery and when the battery reaches 20% SOC, it connects the AC-IN and charges the battery.
And the cycle repeats.
Question:
Is it possible that, during Ignore AC input state/period, to “force” an AC input connect, other than restarting the VE.Bus system?
Unfortunately the 69 and 70 are state registers and therefore because they are only a telltale, are read only.
As for Cerbo’s UI… The same… only a telltale.
Maybe I am missing something? See below.
So, the question stands… Once the system is in an AC-IN disconnected state, how can I force back an AC-IN connect?
Up until now I saw two variants, but they are crude:
restart VE.Bus system, but this will drop for a period of time the AC-Out
modify the Virtual Switch parameters, but then I should modify them back.
The ignore AC in register is not meant to be written to frequently.
So I think the best way to control this is via the inverter mode register: 4= off, 3=on, 2 = invert only.
So in mode 2, the AC input is forced to disconnect, and you can change this one as frequently as you like. This is register 33 and is writeable.
Yes, you are right, but this means that the logic of connecting and disconnecting AC is made by you in some script(s)…
I wanted to use the Virtual switch built in logic and just force, when rarely needed, an AC IN reconnect.
Ha!. So that depends on level of access. If access is no too remote, there is always the off switch for the inverter’s AC in connection, If access is remote, then you can do this manually through the GUI.
It’s remote.
Can you please point out where “you can do this manually through the GUI” ?
GUI-v1, if possible, as the most stable for my situation is Venus OS 3.32 where there is no GUI-v2…
You are saying that if, during Ignore AC-IN state, when the AC-IN is disconnected, I switch from ON to Inverter only and then back to ON, then the Multi will get out of Ignore AC-IN state?
Because I cannot switch to Charger Only or OFF because it will drop the AC loads and that is not acceptable…
If you Select “inverter only”, then that is what it does - It won’t charge from the mains. Whilst this does NOT give the fall back of charging if you get down to 20% SOC, this is the best that can be done without custom scripts.
Then you select 'ON" if you need to charge the battery. AC loads are not dropped when you do this.
Also, I don’t think this will change the state of the ‘ignore AC in’; you would have to disable that, and just use invert only to ignore the ac in.
OK, if I can’t do anything without scripts, then that’s it…
I was trying to keep a lean mean machine, using only built in things like virtual switch, in order to cycle the battery 100-20-100.
And just trying to find a solution to forcibly reconnect AC-IN, if necessary, although this is not a must.
Ideally, if it were possible to disable Virtual Switch from GUI it would be ideal.
When Virtual switch is disabled, then the Multi behaves as Keep charged.
I will try to find how the Virtual Switch is enabled and disable through remote VEConfig and replicate the process from the OS prompt.
And then integrate it with GUI.
Hoped that someone knows how to do that…
Hi Alex, with lithiums, why would you want to cycle the battery? If the AC load demand is light relative to the battery size, then you can set the charge voltage low to leave the battery at 75% - 80%. Then you can leave this on ignore AC in, the system will go fine. Also, if the battery is at 30-40%, again, why would you want to charge it to 100%? Balancing should be ok, as long as you have several hours at 75 - 80% every week, for a light cycle. With Lithiums, most of the corrosion damage occurs above 80% charge, and discharge below 10% also shortens life. Other than that, leaving them sitting at 50 - 80% is fine.
That it’s a interesting idea to explore… Thanks for suggestion.
I could disable the Virtual Switch and set the Absorption voltage to charge the battery to 100%, BUT the float voltage to a value where the battery will be discharged down to 70% and kept there.
And then set the repeated absorption to something like 30 days, when the battery will be brought back, for a very brief period to 100%, in order to balance it a little.
I think that register just gives a readback of the switch position (on - off) but (?) is read only.
Virtual switch configuration also appears in the 7.3.12.2 Settings registers
However, as this is a ‘setting’ I don’t think that it can be changed frequently. This could eventually destroy the internal eeprom and render the inverter inoperative.
Problem about the system is that it’s a Multiplus2-GX, with a nanopi inside.
So, I must, somehow, be a man-in-the-middle for the already connected Multi with a GX, that already uses a serial port for communicating with Multi…
Question is, if the float is set to such low value, in order for the battery to sit at about 70%, when it will switch back to bulk to start a new charging cycle?
With lithium you don’t have storage and rebulk offsets in VE configure…
