I am trying to diagnose a problem with a Victron hybrid/backup system with 1000Ah gel batteries. They have 2x multiplus II 48/5000 operating parallel, firmware version 498. When charging from AC, the battery voltage will rise up to the charge target voltage of 57.6V but it won’t reduce as the battery temperature increases above 25deg C. The batteries are getting up to 32deg C before the AC input is manually turned off. The Multiplus inverters are configured with temperature compensation of -96mV/deg. So at 32deg, I would expect the charge voltage to reduce to 56.9V, but its not, it just stays at 57.6V.
The day time temperatures here are regularly mid 30’s this time of year.
The system also has a BMV-712 battery monitor with a temperature sensor. It has a Smart Solar MPPT which is turned off at the moment.
According to the VRM, both the BMV and Multiplus report exactly (suspiciously) the same battery temperature. Could it using one sensor and displaying the same value in different places. Both the master and slave multiplus have the same temp comp and charge voltage setting.
I can’t find much information regarding the battery temperature compensation and how it works in a system with more than one sensor.
Any help or ideas with this would be greatly appreciated.