Is the message from the battery bank or the inverter?
If it is an ess system then the battery low (if it is a ve bus warning) is coming from the dynamic cut off voltage set in the ess assistant.
If it is from the battery itself sometimes it is a low cell or two.
As an fyi if you are using pylontec then 10% is the minimum soc to set as they only want 90% of their capacity discharged.
To be honest most battery manufacturers would rather you left the bottom 10% alone. (Some a bit more)