Battery Imbalance even if the cells are at the same voltage

My system is located in a yacht which is lquite some distance from where I live. Is there any way to monitor the status of the battery balance remotely on VRM?

I turned off the chargig via VRM with the SoC 100%. When turned ON again after 10 mins the voltage remained at 27V. At what level of SoC should the charging voltage switch to 28,4V?