I have a multiplus II not connected to the grid and a PV pannel grid inverter connected to AC1
I selected lifepo4 as tarting battery type but changed the settings absorprtion voltage to 55.2 and float voltage also to 55.2. The inverter kept charging to above 57V until the cell over protection kicked in.
I'm I missing a setting here ?
These are the settings. Screenshot short after the overvoltage kicked in (voltage is still above 55.2V at this moment)
I selected lifepo4 as tarting battery type but changed the settings absorprtion voltage to 55.2 and float voltage also to 55.2
You might want to expand on this. Post some screenshots of your settings also.
My suspicion would lie with the AC Grid PV system. Does the AC respond to frequency shifting? Does it feedback to the grid? Are there any comms with the multi?
the grid system is an apsystem qs1. There is no grid connection on the multiplus so only the AC1 out is used where a QS1 is connected.
If I understand frequency shifting it should increase the frequency so pushing out the PV inverter but the frequency stayed around 50Hz as you can see on the screenshot. The screenshot i uploaded was from just before the disconnect.
Multiplus was at the moment of the test disconnected from my raspberry pi gx and directly connected to my laptop with the ve configure app open.
You have to install the PV inverter assistant.
https://www.victronenergy.com/live/assistants:pv-inverter-support
have you installed the PV assistant in the multi.
You need to give us a DETAILED setup description as your setup is too vag to answer
2 things to add.
Your VE Configure is outdated.
You are using the multi to measure SOC? Yukk
Third thought, probe the multi via Victron Connect.
I checked the VE configure software and it is up to date. Installation was just a few days old so was expecting it was the latest version. My SOC will be measured with a shunt but that one doesn't want to connect to my GX on my reaspberry PI but could be my own ve-direct cable even that it works with my smartsolar. Victron connect doesn't want to connect to the multiplus on my PC. No idea what the issue is on that level.
Sorry I'm setting my first steps with victron here so still learning and making mistakes I guess.
Multiplus connected to LiFePo4 battery 48v (16 cell 280AH), On AC1 out I have connected on circuit with an apsystem QS1 connected between. From AC1 there is a 30mA earth leak switch (could be too sensitive), a 20A breaker and than the circuit with the QS1. I didn't use the PV assistant. Will test this. Tought it was only whe connected to grid to configure grid feedback ...
First step is finding the frequency settings of the QS1 since it looks I need them for the PV assist ;-)
Update:
tested it with the default PV assistant settings and it looks to work fine. Frequency is increasing, multiplus is in absorption and the current in the battery fluctuates between -0.9A to 5A. Voltage is slightly above 55.2 and now fluctuating between 55.36 and 55.45
Thanks a lot
For testing Try 50.3 to 51.5 the grid tie unit should de rate by 10% on every 0.1Hz increase above 50.3Hz and it should be fully off by 51.5Hz you can use a wider margin also say 50.3 to 53Hz
most country's have different setup specs
If you have not setup a assistant then the system will overcharge the batteries or over voltage the 220 v as the PV power has nowhere else to go.
Thats if the batteries are full and you are using less than what the grid tie is outputting
