I recently installed a Multiplus II 5000 with two Pytes 48100R batteries and configured it as specified in Victron & Pytes [Victron Energy].
Everything is running fine so far, but when I reduce the minimum SoC to 5% or 0% (from the default 10%) the Multiplus starts charging the batteries from the grid with full power as soon as the SoC drops below ~10%.
Then for sure the developers though that less than 10% is not recommended at all and for sure is not good for any battery, regardless of chemistry.
I, for one, never went so low and didn’t know that also the “without” is behaving the same way.
It’s not recommended to go below 10% regularly.
The voltage of a LiFePO4 battery starts to drop faster below 15-10%.
Maybe the low voltage triggers the charging?
What battery do you have? What are the VE.config settings?
I decreased the minimum SoC below 10% at 20:30 and it immediately starts discharging the battery for ~15 minutes. Then re-charge at full-current kicks in. The voltage at that point is 49.9 V which is above all thresholds.