diff --git a/lib/screens/energy_screen.dart b/lib/screens/energy_screen.dart
index 31e0fdf..6cb0216 100644
--- a/lib/screens/energy_screen.dart
+++ b/lib/screens/energy_screen.dart
@@ -54,6 +54,7 @@ class _EnergyScreenState extends State<EnergyScreen> {
     super.initState();
     WidgetsBinding.instance.addPostFrameCallback((_) {
       _nymeaService = context.read<NymeaService>();
+      if (!_nymeaService!.connected) _nymeaService!.startSimulation();
       _nymeaService!.addListener(_onServiceChangedForSoc);
       _fetch();
     });
@@ -298,7 +299,8 @@ class _EnergyScreenState extends State<EnergyScreen> {
     }
 
     final xInterval = _xInterval();
-    final labelStyle = EtmTokens.sans(size: 9, color: EtmTokens.muted);
+    final labelStyle  = EtmTokens.sans(size: 9, color: EtmTokens.muted);
+    final yInterval   = yMax / 4; // 5 graduations : 0, 25%, 50%, 75%, 100% de yMax
 
     return LineChart(
       LineChartData(
@@ -308,52 +310,67 @@ class _EnergyScreenState extends State<EnergyScreen> {
         gridData: FlGridData(
           show: true,
           drawVerticalLine: false,
+          horizontalInterval: yInterval,
           getDrawingHorizontalLine: (_) =>
               FlLine(color: EtmTokens.line, strokeWidth: 1),
         ),
         borderData: FlBorderData(show: false),
         titlesData: FlTitlesData(
           topTitles: const AxisTitles(sideTitles: SideTitles(showTitles: false)),
+
+          // Axe gauche : kW
           leftTitles: AxisTitles(
-            axisNameWidget: Text('kW', style: EtmTokens.sans(size: 9, color: EtmTokens.muted)),
-            axisNameSize: 14,
             sideTitles: SideTitles(
               showTitles: true,
-              reservedSize: 42,
-              getTitlesWidget: (v, _) => Text(
-                v.toStringAsFixed(1),
-                style: labelStyle,
-                textAlign: TextAlign.right,
-              ),
+              reservedSize: 46,
+              interval: yInterval,
+              getTitlesWidget: (v, meta) {
+                if (v == meta.max) return const SizedBox.shrink(); // évite label dupliqué au sommet
+                return SideTitleWidget(
+                  meta: meta,
+                  child: Text(
+                    '${v.toStringAsFixed(1)}kW',
+                    style: labelStyle,
+                  ),
+                );
+              },
             ),
           ),
+
+          // Axe droit : SOC %
           rightTitles: hasSoc
               ? AxisTitles(
-                  axisNameWidget: Text('%', style: EtmTokens.sans(size: 9, color: EtmTokens.green)),
-                  axisNameSize: 14,
                   sideTitles: SideTitles(
                     showTitles: true,
-                    reservedSize: 34,
-                    interval: yMax / 4,
-                    getTitlesWidget: (v, _) {
+                    reservedSize: 40,
+                    interval: yInterval,
+                    getTitlesWidget: (v, meta) {
+                      if (v == meta.max) return const SizedBox.shrink();
                       final pct = (v / yMax * 100).round();
                       if (pct < 0 || pct > 100) return const SizedBox.shrink();
-                      return Text('$pct%',
-                          style: EtmTokens.sans(size: 9, color: EtmTokens.green));
+                      return SideTitleWidget(
+                        meta: meta,
+                        child: Text(
+                          '$pct%',
+                          style: EtmTokens.sans(size: 9, color: EtmTokens.green),
+                        ),
+                      );
                     },
                   ),
                 )
               : const AxisTitles(sideTitles: SideTitles(showTitles: false)),
+
+          // Axe bas : temps
           bottomTitles: AxisTitles(
             sideTitles: SideTitles(
               showTitles: true,
-              reservedSize: 20,
+              reservedSize: 22,
               interval: xInterval,
-              getTitlesWidget: (v, _) {
+              getTitlesWidget: (v, meta) {
                 final idx = v.round();
                 if (idx < 0 || idx >= _data.length) return const SizedBox.shrink();
-                return Padding(
-                  padding: const EdgeInsets.only(top: 4),
+                return SideTitleWidget(
+                  meta: meta,
                   child: Text(_fmtTime(_data[idx].timestamp), style: labelStyle),
                 );
               },
@@ -457,22 +474,28 @@ class _EnergyScreenState extends State<EnergyScreen> {
           leftTitles: AxisTitles(
             sideTitles: SideTitles(
               showTitles: true,
-              reservedSize: 46,
-              getTitlesWidget: (v, _) => Text(_fmtWh(v),
-                  style: labelStyle, textAlign: TextAlign.right),
+              reservedSize: 52,
+              interval: maxE * 1.15 / 4,
+              getTitlesWidget: (v, meta) {
+                if (v == meta.max) return const SizedBox.shrink();
+                return SideTitleWidget(
+                  meta: meta,
+                  child: Text(_fmtWh(v), style: labelStyle),
+                );
+              },
             ),
           ),
           bottomTitles: AxisTitles(
             sideTitles: SideTitles(
               showTitles: true,
-              reservedSize: 20,
-              getTitlesWidget: (v, _) {
+              reservedSize: 22,
+              getTitlesWidget: (v, meta) {
                 final idx  = v.toInt();
                 if (idx < 0 || idx >= _data.length) return const SizedBox.shrink();
                 final step = _xInterval().toInt().clamp(1, _data.length);
                 if (idx % step != 0) return const SizedBox.shrink();
-                return Padding(
-                  padding: const EdgeInsets.only(top: 4),
+                return SideTitleWidget(
+                  meta: meta,
                   child: Text(_fmtTime(_data[idx].timestamp), style: labelStyle),
                 );
               },
diff --git a/lib/services/nymea_service.dart b/lib/services/nymea_service.dart
index f073330..5eb4150 100644
--- a/lib/services/nymea_service.dart
+++ b/lib/services/nymea_service.dart
@@ -125,9 +125,11 @@ class NymeaService extends ChangeNotifier {
 
   /// Retourne {thingId, stateName} de la première batterie trouvée,
   /// ou null si aucune batterie configurée / pas encore chargée.
-  /// Non disponible en simulation (fetchHistory retourne des W, pas des %).
   Map<String, String>? get batterySOCSource {
-    if (_isSimulation) return null;
+    // En simulation : retourne directement la batterie simulée.
+    if (_isSimulation) {
+      return {'thingId': 'sim-battery', 'stateName': 'soc'};
+    }
     if (_things.isEmpty) {
       _log('🔋 batterySOCSource: things pas encore chargés', force: true);
       return null;
@@ -1137,14 +1139,24 @@ class NymeaService extends ChangeNotifier {
     String sampleRate = 'SampleRate15Mins',
   }) async {
     if (_isSimulation) {
-      // Données sinusoïdales simulées
+      // SOC simulé : charge dans la journée (solaire) puis décharge le soir.
+      // Valeurs en % (0-100) pour être normalisables côté graphe.
       final entries = <HistoryEntry>[];
       const steps = 48;
       final step = to.difference(from) ~/ steps;
       for (int i = 0; i <= steps; i++) {
         final t = from.add(step * i);
-        final v = 500 + 400 * sin(i * pi / 12);
-        entries.add(HistoryEntry(timestamp: t, value: v));
+        final hour = t.hour + t.minute / 60.0;
+        // Montée solaire 8h-15h → 20% → 85%, descente soir → 20%
+        final double soc;
+        if (hour < 8) {
+          soc = 20 + 5 * (hour / 8);
+        } else if (hour < 15) {
+          soc = 25 + 60 * ((hour - 8) / 7);
+        } else {
+          soc = 85 - 65 * ((hour - 15) / 9);
+        }
+        entries.add(HistoryEntry(timestamp: t, value: soc.clamp(5.0, 95.0)));
       }
       return entries;
     }