Wondering if anyone has seen this before. I have a Conversol Max 11kW unit connected to 25kW of LiFePo batteries. The Low Voltage Cutoff is set to 48V and the Back to Grid Voltage is set to 49V. You can see from the graph attached that the unit stops taking current from the batteries at 49V as expected, but overnight and into today the voltage on the batteries has continued to sag. Any ideas why this is happening? The PV today isn't sufficient to cover house load and the battery charging, so it's running in solar/grid blend and sending it straight to the load. I would have expected the cutoff battery voltage to be stable while no charging/discharging is taking place.

Just leaving a note in the event anyone ever needs any information on this, I got around the issue by changing the back to grid voltage to 51V instead of 49V to leave extra capacity. A little less practical, but I'm able to change the inverter settings using node red and MQTT for particular times of the year. When I get to October, when the batteries usually don't get a full charge every day, using "Big timer" I automatically change the back to grid voltage to 51V. When the time of year hits March, where the batteries get fully charged most days, the back to grid voltage will automatically be set to 49V again to enable maximum battery use.