ESS #5 is slowly draining the battery instead of charging

In pass-through mode, the ESS system (with batterylife enabled) is very slowly draining the battery at about -0.5Ah (for 820Ah LFP battery bank) even though:

  • It is already 5% below minimum 80% SOC
  • Inverter is in pass-through mode since the grid is available - no power failures in past few days
  • ESS is in #5 mode, and claims to be slowly charging the battery

It is a Quattro inverter set up with Cerbo GX and SmartShunt battery monitor. The system is grid-tie, and is in pass-through mode. Screenshot attached.

Will appreciate help with resolving it. I looked in ESS manual but found nothing about this condition.

Turns out this was due to “Grid Metering” in ESS being set to “External Meter” (when none is installed) instead of “Inverter/Charger”. Setting it to “Inverter/Charger” fixed the issue. Now, it is indeed charging, and the layout also changes since Inverter is now measuring the energy flow through it.

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