From 72b7e270570241713dbda2c59421acc5d7dcc750 Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Wed, 19 Aug 2026 08:50:24 +0200
Subject: [PATCH] Loadpoint: sync charger phases on vehicle connect (#32962)

---
 core/loadpoint.go        | 37 ++++++++---------------------------
 core/loadpoint_phases.go | 42 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 29 deletions(-)

diff --git a/core/loadpoint.go b/core/loadpoint.go
index ee0884870..69d21af59 100644
--- a/core/loadpoint.go
+++ b/core/loadpoint.go
@@ -561,6 +561,11 @@ func (lp *Loadpoint) evVehicleConnectHandler() {
 	// soc update reset
 	lp.socUpdated = time.Time{}
 
+	// charger may have reconfigured phases internally while disconnected
+	if err := lp.syncChargerPhases(); err != nil {
+		lp.log.ERROR.Println(err)
+	}
+
 	// set default or start detection
 	if !lp.chargerHasFeature(api.IntegratedDevice) {
 		lp.vehicleDefaultOrDetect()
@@ -884,35 +889,9 @@ func (lp *Loadpoint) syncCharger() error {
 		}
 
 		// sync phases
-		_, isPs := api.Cap[api.PhaseSwitcher](lp.charger)
-		if phases := lp.GetPhases(); isPs && shouldBeConsistent && phases > 0 {
-			// fallback to active phases from measured phases
-			chargerPhases := lp.measuredPhases
-			if chargerPhases == 2 {
-				chargerPhases = 3
-			}
-
-			pg, isPg := api.Cap[api.PhaseGetter](lp.charger)
-			if isPg {
-				if chargerPhases, err = pg.GetPhases(); err == nil {
-					if chargerPhases > 0 && chargerPhases != phases {
-						lp.log.WARN.Printf("charger logic error: phases mismatch (got %d, expected %d)", chargerPhases, phases)
-						lp.SetPhases(chargerPhases)
-					}
-				} else {
-					if errors.Is(err, api.ErrNotAvailable) {
-						return nil
-					}
-					return fmt.Errorf("charger get phases: %w", err)
-				}
-			}
-
-			// use measured phase currents for active phases as fallback if charger does not provide phases
-			if !isPg || errors.Is(err, api.ErrNotAvailable) {
-				if chargerPhases > phases {
-					lp.log.WARN.Printf("charger logic error: phases mismatch (got %d measured, expected %d)", chargerPhases, phases)
-					lp.SetPhases(chargerPhases)
-				}
+		if shouldBeConsistent {
+			if err := lp.syncChargerPhases(); err != nil {
+				return err
 			}
 		}
 
diff --git a/core/loadpoint_phases.go b/core/loadpoint_phases.go
index 207ef9234..50d9e8f2a 100644
--- a/core/loadpoint_phases.go
+++ b/core/loadpoint_phases.go
@@ -1,6 +1,9 @@
 package core
 
 import (
+	"errors"
+	"fmt"
+
 	"github.com/evcc-io/evcc/api"
 	"github.com/evcc-io/evcc/core/keys"
 )
@@ -161,3 +164,42 @@ func (lp *Loadpoint) getChargerPhysicalPhases() int {
 func (lp *Loadpoint) hasPhaseSwitching() bool {
 	return api.HasCap[api.PhaseSwitcher](lp.charger)
 }
+
+// syncChargerPhases synchronizes the assumed phase state with the charger's actual state.
+// Chargers may reconfigure phases internally, i.e. when the vehicle is (dis)connected.
+func (lp *Loadpoint) syncChargerPhases() error {
+	phases := lp.GetPhases()
+	if !lp.hasPhaseSwitching() || phases <= 0 {
+		return nil
+	}
+
+	if pg, ok := api.Cap[api.PhaseGetter](lp.charger); ok {
+		chargerPhases, err := pg.GetPhases()
+		if err != nil {
+			if errors.Is(err, api.ErrNotAvailable) {
+				return nil
+			}
+			return fmt.Errorf("charger get phases: %w", err)
+		}
+
+		if chargerPhases > 0 && chargerPhases != phases {
+			lp.log.WARN.Printf("charger logic error: phases mismatch (got %d, expected %d)", chargerPhases, phases)
+			lp.SetPhases(chargerPhases)
+		}
+
+		return nil
+	}
+
+	// use measured phase currents for active phases as fallback if charger does not provide phases
+	chargerPhases := lp.GetMeasuredPhases()
+	if chargerPhases == 2 {
+		chargerPhases = 3
+	}
+
+	if chargerPhases > phases {
+		lp.log.WARN.Printf("charger logic error: phases mismatch (got %d measured, expected %d)", chargerPhases, phases)
+		lp.SetPhases(chargerPhases)
+	}
+
+	return nil
+}