From d96374b5f9e36b68cfea9ed80b55fde7276b52ac Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmail.com>
Date: Wed, 27 May 2026 13:36:07 +0200
Subject: [PATCH] Add battery feed-in priority limit

---
 core/keys/site.go    |  3 +++
 core/site.go         |  6 +++++-
 core/site_api.go     | 30 ++++++++++++++++++++++++++++++
 core/site_battery.go |  8 +++++++-
 4 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/core/keys/site.go b/core/keys/site.go
index 8ea653b9822..4aaa8d36829 100644
--- a/core/keys/site.go
+++ b/core/keys/site.go
@@ -44,6 +44,9 @@ const (
 	BufferSoc               = "bufferSoc"
 	BufferStartSoc          = "bufferStartSoc"
 
+	BatteryFeedInPriorityLimit  = "batteryFeedInPriorityLimit"
+	BatteryFeedInPriorityActive = "batteryFeedInPriorityActive"
+
 	// battery status
 	Battery     = "battery"
 	BatteryMode = "batteryMode"
diff --git a/core/site.go b/core/site.go
index 48a8dbbc7ab..6791df628f3 100644
--- a/core/site.go
+++ b/core/site.go
@@ -79,6 +79,8 @@ type Site struct {
 	batteryDischargeControl bool     // prevent battery discharge for fast and planned charging
 	batteryGridChargeLimit  *float64 // grid charging limit
 
+	batteryFeedInPriorityLimit *float64 // disable battery charge and prefer feed-in at this limit
+
 	loadpoints  []*Loadpoint             // Loadpoints
 	tariffs     *tariff.Tariffs          // Tariffs
 	coordinator *coordinator.Coordinator // Vehicles
@@ -1025,7 +1027,9 @@ func (site *Site) update(lp updater) {
 	// update battery after reading meters to ensure that (modbus) connection is open
 	batteryGridChargeActive := site.batteryGridChargeActive(rate)
 	site.publish(keys.BatteryGridChargeActive, batteryGridChargeActive)
-	site.updateBatteryMode(batteryGridChargeActive, rate)
+	batteryFeedInPriorityActive := site.batteryFeedInPriorityActive(rate)
+	site.publish(keys.BatteryFeedInPriorityActive, batteryFeedInPriorityActive)
+	site.updateBatteryMode(batteryGridChargeActive, batteryFeedInPriorityActive, rate)
 
 	site.stats.Update(site)
 }
diff --git a/core/site_api.go b/core/site_api.go
index b079039d8d3..472b4cb2a96 100644
--- a/core/site_api.go
+++ b/core/site_api.go
@@ -371,6 +371,36 @@ func (site *Site) SetBatteryGridChargeLimit(val *float64) error {
 
 	return nil
 }
+func (site *Site) GetBatteryFeedInPriorityLimit() *float64 {
+	site.RLock()
+	defer site.RUnlock()
+	return site.batteryFeedInPriorityLimit
+}
+
+func (site *Site) SetBatteryFeedInPriorityLimit(val *float64) error {
+	site.log.DEBUG.Println("set feed-in priority limit:", printPtr("%.1f", val))
+
+	if !site.hasBatteryControl() {
+		return ErrBatteryControlNotAvailable
+	}
+
+	site.Lock()
+	defer site.Unlock()
+
+	if !ptrValueEqual(site.batteryFeedInPriorityLimit, val) {
+		site.batteryFeedInPriorityLimit = val
+
+		if val == nil {
+			settings.SetString(keys.BatteryFeedInPriorityLimit, "")
+			site.publish(keys.BatteryFeedInPriorityLimit, nil)
+		} else {
+			settings.SetFloat(keys.BatteryFeedInPriorityLimit, *val)
+			site.publish(keys.BatteryFeedInPriorityLimit, *val)
+		}
+	}
+
+	return nil
+}
 
 // GetBatteryMode returns the battery mode
 func (site *Site) GetBatteryMode() api.BatteryMode {
diff --git a/core/site_battery.go b/core/site_battery.go
index a052bc74ccc..ca586398c61 100644
--- a/core/site_battery.go
+++ b/core/site_battery.go
@@ -52,7 +52,8 @@ func (site *Site) SetBatteryMode(batMode api.BatteryMode) {
 	}
 }
 
-func (site *Site) updateBatteryMode(batteryGridChargeActive bool, rate api.Rate) {
+// TODO implement batteryFeedInPriorityActive
+func (site *Site) updateBatteryMode(batteryGridChargeActive, batteryFeedInPriorityActive bool, rate api.Rate) {
 	batteryMode := site.requiredBatteryMode(batteryGridChargeActive, rate)
 
 	// put battery into hold mode when charging is active and circuit dimmed
@@ -202,6 +203,11 @@ func (site *Site) batteryGridChargeActive(rate api.Rate) bool {
 	return limit != nil && !rate.IsZero() && rate.Value <= *limit
 }
 
+func (site *Site) batteryFeedInPriorityActive(rate api.Rate) bool {
+	limit := site.GetBatteryFeedInPriorityLimit()
+	return limit != nil && !rate.IsZero() && rate.Value <= *limit
+}
+
 func (site *Site) dischargeControlActive(rate api.Rate) bool {
 	if !site.GetBatteryDischargeControl() {
 		return false