From 2b16c415bbb1a588638645a668e4c09be657dd7e Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Fri, 8 May 2026 09:20:51 +0200
Subject: [PATCH] Fritz: make unit 1-based (BC) (#29741)

---
 meter/fritz/smarthome/smarthome.go          | 4 ++--
 meter/fritzdect.go                          | 5 ++++-
 templates/definition/charger/fritzdect.yaml | 1 +
 templates/definition/meter/fritzdect.yaml   | 1 +
 templates/definition/meter/fritzgrid.yaml   | 1 +
 5 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/meter/fritz/smarthome/smarthome.go b/meter/fritz/smarthome/smarthome.go
index 23a75ac32..ef9db252a 100644
--- a/meter/fritz/smarthome/smarthome.go
+++ b/meter/fritz/smarthome/smarthome.go
@@ -88,10 +88,10 @@ func (c *Connection) resolveUnitUID(unit int) (string, error) {
 		if d.AIN != c.AIN {
 			continue
 		}
-		if len(d.UnitUids) < unit+1 {
+		if len(d.UnitUids) < unit {
 			return "", fmt.Errorf("invalid unit %d, got %v", unit, d.UnitUids)
 		}
-		return d.UnitUids[unit], nil
+		return d.UnitUids[unit-1], nil
 	}
 
 	return "", fmt.Errorf("ain not found: %s", c.AIN)
diff --git a/meter/fritzdect.go b/meter/fritzdect.go
index caa281e1f..d25e5b513 100644
--- a/meter/fritzdect.go
+++ b/meter/fritzdect.go
@@ -18,7 +18,10 @@ func init() {
 
 // NewFritzDECTFromConfig creates a fritzdect meter from generic config
 func NewFritzDECTFromConfig(other map[string]any) (api.Meter, error) {
-	var cc fritz.Settings
+	cc := fritz.Settings{
+		Unit: 1,
+	}
+
 	if err := util.DecodeOther(other, &cc); err != nil {
 		return nil, err
 	}
diff --git a/templates/definition/charger/fritzdect.yaml b/templates/definition/charger/fritzdect.yaml
index 2d75a7ddd..509168375 100644
--- a/templates/definition/charger/fritzdect.yaml
+++ b/templates/definition/charger/fritzdect.yaml
@@ -39,6 +39,7 @@ params:
   - name: unit
     advanced: true
     type: int
+    default: 1
     description:
       de: Einheit
       en: Unit
diff --git a/templates/definition/meter/fritzdect.yaml b/templates/definition/meter/fritzdect.yaml
index c4ca34a97..1a659d54f 100644
--- a/templates/definition/meter/fritzdect.yaml
+++ b/templates/definition/meter/fritzdect.yaml
@@ -40,6 +40,7 @@ params:
   - name: unit
     advanced: true
     type: int
+    default: 1
     description:
       de: Einheit
       en: Unit
diff --git a/templates/definition/meter/fritzgrid.yaml b/templates/definition/meter/fritzgrid.yaml
index 125ea2cbd..5f683e469 100644
--- a/templates/definition/meter/fritzgrid.yaml
+++ b/templates/definition/meter/fritzgrid.yaml
@@ -18,6 +18,7 @@ params:
   - name: unit
     advanced: true
     type: int
+    default: 1
     description:
       de: Einheit
       en: Unit