I just changed my batteries from wet cell to AGM. It was charged for several hours and showed 100% charge. We ran the boat for an hour afterwards and the BMV showed that the batteries were receiving a charge. We sat in the sun, getting some amperage. We used the batteries for some low useage activitie, such as a small fan and of course the refrigerator. Then we ran the boat for another hour. At the end of that period the BMV showed we had used 50 amp hours, with a SOC of 92%. At that point I realized that I had not changed the battery capacity. I changed it to match the batteries. The next morning I checked the voltage using two different volt meters. They showed 25.96v while the BMV showed 24.41. I never had that happen with the previous batteries.
There are two AGM 161 ah batteries and two starter batteries. There is a Victron 24v inverter, just a year old. There is a Victron Solar MPPT 75/ 15regulator that has been working well. , The BMV is about 2 months old.
I can not find anything stating that there is a different setting for AGM batteries. Mine are made by Genois, a Polish manufacturer.
Why does BMV show the wrong voltage and how do I correct it?