Repeatable ESS/DVCC bug: SmartSolar MPPT remains limited until AC load changes

Title: SmartSolar MPPT output remains limited until AC load changes

System:

  • Cerbo GX MK1
  • Venus OS v3.75 (same behavior on v3.73)
  • SmartSolar MPPT 250/100 connected via VE.Can
  • 3x MultiPlus-II
  • Fronius Symo
  • Pylontech batteries
  • ESS enabled
  • DVCC enabled

Issue:

I have found a repeatable issue.

When the battery is around 99-100% SOC and a large continuous AC load (heat pump approximately 3 kW) is running, the SmartSolar MPPT sometimes remains at a much lower output than the available PV power.

The Fronius inverter continues producing normally.

If I switch the heat pump OFF for only a few seconds, the MPPT immediately starts increasing its output to the expected value.

When I switch the heat pump ON again, the MPPT continues operating normally at full power.

This behavior is repeatable.

Previously I thought restarting the Cerbo solved the issue, but after further testing I found that simply changing the AC load is enough to trigger an immediate recalculation and the MPPT ramps up correctly.

It looks like ESS/DVCC or the external MPPT control does not always recalculate the available PV power correctly until the AC load changes.

Has anyone else observed similar behavior?