I am on a sailboat and we have four 100 Amph AGM batteries that are powered by six solar panels and alternators on the Diesel engines. That butteries are less than 5 years old. I did not install the system and am beginning to learn how it works. A Phoenix Multiplus controls the charging input. Right now the BMV 501 meter says the batteries are at 97% but voltage says 11.0V. A multimeter reading at the battery bank shows a reading of 13.0V under no charge/discharge condition. Can anyone help me start to investigate what’s going on? Thanks Rob.