Hello,
I have a multiplus II 5000/48 , fronius primo 4 , BYD LVS premium 4Kwhr battery and 6 Q-cells panels (580kw/panel).
Is the difference in maximum and minimum cell voltage (during day only) healthy?
asked
Battery cell voltages
Is this a new(ish) install?
Are the batteries getting a full charge regularly?
You would expect imbalances under charge on newer batteries, or where they aren't getting to properly charge regularly enough, though 4kWh isn't a lot of battery for a 5k inverter.
It should sort itself out with time if allowed to charge/remain charged often enough.
I installed this system from 8 months, the battery is getting regularly fully charged
It should have sorted itself by now then. 4kWh isn’t a lot, so not knowing how it is being used, history etc it’s difficult to say. Is it the same cells reporting the difference or does it vary?
Could be how it is being used, could be a cell.
All things being equal, and used within spec, you shouldn’t have large imbalances after 8 months.
Edit:
Looking at your previous posts about ripple, comments on undersized battery and high-voltage warnings, your issues are probably more related to stressing the battery and the BMS. Can't expect optimal performance in those conditions.
not healthy at all. expect regular HVD by the BMS?
What do you think is the suitable solution for these problems?
Thank you
BYD on grid should charge to 55.2v every day. The graph is not so clear, if you zoom in you will be able to check.
With the BMU you can check each cell individually with the BE Connect App over its own WiFi.
Each cell should reach 3.45v each absorption.
Floating at 3.43v
Low cut off should be around 2.95v each cell.
If the battery is having issues, events will be logged in on the BMU. You can see them there
Thank you Alexandra,
If I keep my system on one 4Kwhr battery only, may that be harmful to my system, or I must add another BYD battery?
Thanks again
I am always in favor of adding more battery, especially if you are heavy cycling the battery down to low SOC.
