diff --git a/backend/services/planning/solver_v2.py b/backend/services/planning/solver_v2.py
index c0cb900..6b4a704 100644
--- a/backend/services/planning/solver_v2.py
+++ b/backend/services/planning/solver_v2.py
@@ -17,6 +17,11 @@
 #   - zákaz současného importu a exportu (binárka)
 #   - load-first Deye: bc_pv + ge_pv jen z PV přebytku nad zátěží
 #   - EV deadline, TUV look-ahead, provozní režimy (legitimní constraints)
+#   - noční SoC polštář: plán nesmí kalkulovat s vybitím až na min_soc — chyba
+#     predikce noční spotřeby by znamenala neplánovaný noční nákup. Velikost
+#     z DB (planner_night_baseload_buffer_percent → slot.night_baseload_buffer_wh,
+#     klesá k 0 do rána); porušení je PLACENÉ cenou buy daného slotu (riziko
+#     zpětného nákupu), takže extrémní sell špička ho smí racionálně prodat.
 #
 # Vědomé odchylky od v1 (změří harness):
 #   - SQL masky allow_charge / allow_discharge_export se IGNORUJÍ (jsou to
@@ -147,6 +152,11 @@ def solve_dispatch_v2(
         for e in range(EV)
     ]
     ev_unmet: list = []  # slack Wh per session (cena V2_EV_UNMET_CZK_KWH)
+    nb_buffer_wh = [max(0.0, float(s.night_baseload_buffer_wh or 0.0)) for s in slots]
+    nb_slack = [
+        pulp.LpVariable(f"nbs_{t}", 0, nb_buffer_wh[t]) if nb_buffer_wh[t] > 0 else None
+        for t in range(T)
+    ]
 
     def _connected(e: int, t: int) -> bool:
         return bool(slots[t].ev1_connected if e == 0 else slots[t].ev2_connected)
@@ -197,6 +207,10 @@ def solve_dispatch_v2(
         prob += ge_bat[t] <= max_exp * z_exp[t], f"zexp_link_{t}"
         prob += soc[t] >= arb_floor - (soc_max - soc_min) * (1 - z_exp[t]), f"zexp_floor_{t}"
 
+        # noční SoC polštář (viz hlavička): soft floor nad min_soc
+        if nb_slack[t] is not None:
+            prob += soc[t] >= soc_min + nb_buffer_wh[t] - nb_slack[t], f"night_buf_{t}"
+
         # tvrdá cenová pravidla
         if float(s.buy_price) < 0.0:
             prob += ge_pv[t] + ge_bat[t] == 0, f"neg_buy_noexp_{t}"
@@ -286,6 +300,13 @@ def solve_dispatch_v2(
         )
     if ev_unmet:
         extras += pulp.lpSum(u * V2_EV_UNMET_CZK_KWH / 1000.0 for u in ev_unmet)
+    nb_terms = [
+        nb_slack[t] / 1000.0 * max(0.0, float(slots[t].buy_price))
+        for t in range(T)
+        if nb_slack[t] is not None
+    ]
+    if nb_terms:
+        extras += pulp.lpSum(nb_terms)
 
     prob += cash + degradation + extras - terminal * soc[T - 1]
 
@@ -386,6 +407,8 @@ def solve_dispatch_v2(
             "slot_count": T,
             "ev_sessions": sum(1 for x in ev_sessions if x is not None),
             "masks_ignored": True,
+            "night_buffer_slots": sum(1 for b in nb_buffer_wh if b > 0),
+            "night_buffer_max_wh": round(max(nb_buffer_wh), 1) if nb_buffer_wh else 0,
         },
         "objective_terms": {
             "cash_czk": round(float(pulp.value(cash)), 3),
diff --git a/backend/tests/test_solver_v2.py b/backend/tests/test_solver_v2.py
index 336ff3a..b730894 100644
--- a/backend/tests/test_solver_v2.py
+++ b/backend/tests/test_solver_v2.py
@@ -154,6 +154,45 @@ class OperatingModeTests(unittest.TestCase):
             self.assertLessEqual(r.grid_setpoint_w, 1000, "import ≤ baseline load")
 
 
+class NightReserveTests(unittest.TestCase):
+    def test_night_discharge_respects_buffer(self) -> None:
+        # noc: vysoký sell, žádné PV; buffer 2000 Wh nad min → plán nesmí
+        # kalkulovat s vybitím pod min+buffer (sell < buy ⇒ slack se nevyplatí)
+        bat = _battery()
+        slots = []
+        for i in range(16):
+            s = _slot(_BASE, i, buy=6.0, sell=4.5, load=800)
+            s.night_baseload_buffer_wh = 2000.0
+            slots.append(s)
+        results, _, _ = _solve(slots, battery=bat, soc0=0.6 * bat.usable_capacity_wh)
+        floor_pct = (bat.min_soc_wh + 2000.0) / bat.usable_capacity_wh * 100.0
+        for r in results:
+            self.assertGreaterEqual(r.battery_soc_target, floor_pct - 0.6)
+
+    def test_extreme_sell_spike_may_sell_reserve(self) -> None:
+        # sell výrazně nad buy → racionální polštář prodat (placený slack)
+        bat = _battery()
+        slots = []
+        for i in range(16):
+            s = _slot(_BASE, i, buy=2.0, sell=12.0, load=300)
+            s.night_baseload_buffer_wh = 2000.0
+            slots.append(s)
+        results, _, _ = _solve(slots, battery=bat, soc0=0.6 * bat.usable_capacity_wh)
+        min_soc_pct = min(r.battery_soc_target for r in results)
+        floor_pct = (bat.min_soc_wh + 2000.0) / bat.usable_capacity_wh * 100.0
+        self.assertLess(min_soc_pct, floor_pct - 1.0, "spike má polštář vyprodat")
+
+    def test_start_below_buffer_is_feasible(self) -> None:
+        bat = _battery()
+        slots = []
+        for i in range(8):
+            s = _slot(_BASE, i, buy=6.0, sell=1.0, load=1500)
+            s.night_baseload_buffer_wh = 3000.0
+            slots.append(s)
+        results, _, _ = _solve(slots, battery=bat, soc0=bat.min_soc_wh + 500.0)
+        self.assertEqual(len(results), 8)
+
+
 class EvDeadlineTests(unittest.TestCase):
     def test_ev_energy_delivered_before_deadline(self) -> None:
         slots = [_slot(_BASE, i, buy=2.0 if i < 8 else 6.0, sell=1.0, ev1=True) for i in range(16)]