RE: 18kPV (FAAB-2727): "Time+SOC" AC charge ignores the Stop-SOC target — charges to full; AC Charge Power setpoint also ignored

sv1985pg — Mon, 06 Jul 2026 20:36:42 +0000

Follow-up / clarification (please disregard my 85% example):

Since posting I identified a SEPARATE issue with my battery's SOC gauge — the pack's
reported State of Charge freezes near 80% and then jumps straight to ~100%, skipping
81–99%. (3rd-party Docan/JBD-type BMS; reported to the battery vendor separately.)

That means my Stop-85% example is NOT clean evidence — the inverter never actually
"saw" 85%. Please set that one aside.

The core finding is unaffected and rests on gauge-independent tests: with Stop SOC set
to 45% — a mid-range value the gauge reports accurately (43 → 45 → 46 → 47 in order) —
"Time + SOC" grid-charged straight through 45% at full rate (~11 kW) with no throttle
and no stop. A Stop-35% test behaved identically. So Time + SOC ignores the Stop-SOC
target regardless of any gauge behavior.

Findings 2 (AC Charge Power setpoint ignored) and 3 (SOC mode stops cleanly at 53%)
are also independent of the gauge. Happy to share the 15-second logs and a chart.

18kPV (FAAB-2727): "Time+SOC" AC charge ignores the Stop-SOC target — charges to full; AC Charge Power setpoint also ignored

sv1985pg — Sun, 05 Jul 2026 21:16:19 +0000

Hardware: EG4 18kPV (18KPV-12LV), firmware FAAB-2727, with a 3rd-party Docan 48 kWh LiFePO₄ in closed-loop (comms confirmed — pack SOC matches the inverter, BMS Charge/Discharge = Allowed).

I logged read-only Modbus telemetry every 15 seconds and ran controlled A/B tests, reading each setting back from the holding registers to confirm it applied. Two behaviors don't match the documentation/UI:

1) "Time + SOC" mode ignores the Stop-SOC target.
Expected: charge during the window and only up to the Stop-SOC, then stop.
Observed: it charges the entire window regardless of SOC, overshooting to full.

Test A: Stop SOC set to 85% at 14:09 — 16 minutes BEFORE the 14:25 window opened (ruling out "changed mid-window"). Battery grid-charged straight through 85% to 99% by the window's end. Net solar (PV − load) was negative after ~15:15, so the whole 56% → 99% climb was grid charging.
Test B (clean retest): Time+SOC, Stop 45%, set before the window, wide band. Charged straight through 45% → 47%+ at full rate, with no throttle at the target.

2733

2) AC Charge Power (kW) setpoint is ignored.

Set to 3 kW → charged ~8.6 kW.
Set to 10 kW → charged ~8.4 kW.
Identical. Actual rate tracked only the BMS charge-current limit (~150 A at 50% SOC, tapering), never the kW setpoint.

3) For contrast — "SOC"-based mode DOES stop correctly (same battery, same live SOC):
With Based On = SOC, Stop 53%, grid draw went 873 W → 0 exactly at 53% and stayed at 0 even as house load rose. This shows the inverter has correct SOC and can act on it — which points the Time+SOC failure at the charge-control logic, not the battery or its comms.

Questions:

Is the Time + SOC behavior (1) intended, or a firmware bug? I expected it to stop at the target within the window.
Is the AC Charge Power (kW) setpoint supposed to cap grid charge current? It appears ignored.
If (1) is intended, what's the supported way to grid-charge to a target SOC within a time window and then stop? (SOC mode stops at target but ignores the window, risking charging during peak-rate hours.)

Happy to share full 15-second logs, register snapshots, and charts. Anyone else on FAAB-2727 seeing the same?

18kPV (FAAB-2727): "Time+SOC" AC charge ignores the Stop-SOC target — charges to full; AC Charge Power setpoint also ignored - 18kPV

RE: 18kPV (FAAB-2727): "Time+SOC" AC charge ignores the Stop-SOC target — charges to full; AC Charge Power setpoint also ignored

18kPV (FAAB-2727): "Time+SOC" AC charge ignores the Stop-SOC target — charges to full; AC Charge Power setpoint also ignored