diff --git a/core/loadpoint.go b/core/loadpoint.go
index cdee2532b..deaddf4cf 100644
--- a/core/loadpoint.go
+++ b/core/loadpoint.go
@@ -63,6 +63,7 @@ const (
 	boostDisabled = 0
 	boostStart    = 1
 	boostContinue = 2
+	boostHold     = 3 // soc limit reached: stop draining but keep vehicle priority over recharging
 )
 
 // elapsed is the time an expired timer will be set to
@@ -1523,7 +1524,7 @@ func (lp *Loadpoint) publishTimer(name string, delay time.Duration, action strin
 // boostPower returns the additional power that the loadpoint should draw from the battery
 func (lp *Loadpoint) boostPower(batteryBoostPower float64) float64 {
 	boost := lp.GetBatteryBoost()
-	if boost == boostDisabled {
+	if boost == boostDisabled || boost == boostHold {
 		return 0
 	}
 
@@ -2042,15 +2043,15 @@ func (lp *Loadpoint) phaseSwitchCompleted() bool {
 
 // Update is the main control function. It reevaluates meters and charger state
 func (lp *Loadpoint) Update(sitePower, batteryBoostPower float64, consumption, feedin api.Rates, batteryBuffered, batteryStart bool, greenShare float64, effPrice, effCo2 *float64, dim *bool) {
-	// auto-disable battery boost when SOC drops below limit
-	if lp.GetBatteryBoost() != boostDisabled {
+	// hold battery boost when SOC drops below the limit: stop draining the battery, but
+	// keep the vehicle prioritised over recharging it (via sitePower priorityAdjustment)
+	// until the vehicle disconnects. This holds the battery at the configured level
+	// instead of the naive on/off which lets the battery recharge and oscillate (#30558).
+	if boost := lp.GetBatteryBoost(); boost != boostDisabled && boost != boostHold {
 		if limit := lp.GetBatteryBoostLimit(); limit < 100 {
 			if batterySoc := lp.site.GetBatterySoc(); batterySoc < float64(limit) {
-				lp.log.DEBUG.Printf("battery boost disabled: soc below limit (%.0f%% < %d%%)", batterySoc, limit)
-
-				if err := lp.SetBatteryBoost(false); err != nil {
-					lp.log.ERROR.Printf("set battery boost: %v", err)
-				}
+				lp.log.DEBUG.Printf("battery boost hold: soc below limit (%.0f%% < %d%%)", batterySoc, limit)
+				lp.setBatteryBoost(boostHold)
 			}
 		}
 	}
diff --git a/core/loadpoint_test.go b/core/loadpoint_test.go
index 642a52421..22d82b4a9 100644
--- a/core/loadpoint_test.go
+++ b/core/loadpoint_test.go
@@ -863,3 +863,22 @@ func TestWelcomeChargeAppliedOnlyOnce(t *testing.T) {
 	welcomeCharge, _ = lp.updateChargerStatus()
 	assert.False(t, welcomeCharge)
 }
+
+// TestBatteryBoostHold verifies that in the hold state (soc limit reached) battery
+// boost no longer draws power from the battery, while still counting as active so
+// the site keeps prioritising the vehicle over recharging the battery (#30558).
+func TestBatteryBoostHold(t *testing.T) {
+	lp := &Loadpoint{log: util.NewLogger("foo")}
+
+	// disabled draws nothing
+	lp.batteryBoost = boostDisabled
+	assert.Equal(t, 0.0, lp.boostPower(2000), "disabled")
+
+	// hold draws nothing (stops draining the battery)...
+	lp.batteryBoost = boostHold
+	assert.Equal(t, 0.0, lp.boostPower(2000), "hold")
+
+	// ...but is still an active boost state (GetBatteryBoost != boostDisabled),
+	// which is what keeps the sitePower priority adjustment applied to the loadpoint
+	assert.NotEqual(t, boostDisabled, lp.GetBatteryBoost(), "hold is active")
+}