diff --git a/scripts/analysis/battery_sizing_screen.py b/scripts/analysis/battery_sizing_screen.py
index 23eb50d..8910bb1 100644
--- a/scripts/analysis/battery_sizing_screen.py
+++ b/scripts/analysis/battery_sizing_screen.py
@@ -5,6 +5,14 @@ Ekonomický screening velikosti baterie (15min, jednobusová energie).
 Typicky BA81: fixní nákup + prodej spot, limity výkonu z baterie min(0,5C, střídač),
 export/import podle připojení. Načte OTE z Postgres (stejná DB jako EMS) nebo z CSV.
 
+Připojení k DB (deploy / Docker):
+  - Postgres v compose poslouchá na ``EMS_DB_BIND:5432`` (výchozí 127.0.0.1). ``connection refused``
+    = služba ``db`` neběží, nebo je port vázaný jen na jinou IP (WireGuard) → nastav stejný host.
+  - Skript načte první nalezené ``.env`` z ``…/ems-deploy/.env`` nebo ``…/app/.env`` (není-li
+    ``--no-auto-env``) a doplní ``PGUSER``/``PGPASSWORD`` z ``DB_USER``/``DB_PASSWORD``.
+  - Nebo ``DATABASE_URL`` / ``postgresql://USER:PASS@HOST:5432/ems`` (na hostu HOST=127.0.0.1
+    nebo EMS_DB_BIND, ne ``db`` — to je jen uvnitř Docker sítě).
+
 Příklad:
   python3 scripts/analysis/battery_sizing_screen.py \\
     --db \\
@@ -31,6 +39,7 @@ import os
 import sys
 from dataclasses import dataclass
 from datetime import date, datetime, timedelta
+from pathlib import Path
 from typing import Iterable, Sequence
 
 try:
@@ -93,6 +102,41 @@ def effective_sell_kc_kwh(raw_ote: float, margin_fixed: float, margin_pct: float
     return raw_ote + margin_fixed + (raw_ote * margin_pct / 100.0)
 
 
+def load_env_file(path: Path) -> None:
+    if not path.is_file():
+        return
+    for line in path.read_text(encoding="utf-8", errors="replace").splitlines():
+        line = line.strip()
+        if not line or line.startswith("#") or "=" not in line:
+            continue
+        k, _, v = line.partition("=")
+        k, v = k.strip(), v.strip().strip('"').strip("'")
+        if not k:
+            continue
+        if k not in os.environ or os.environ.get(k, "") == "":
+            os.environ[k] = v
+
+
+def apply_auto_env_files() -> None:
+    """Na produkci: /opt/ems-deploy/.env (když tam je docker-compose), pak app/.env nebo kořen repa."""
+    script = Path(__file__).resolve()
+    if len(script.parents) >= 3:
+        deploy_root = script.parents[2]
+        if (deploy_root / "docker-compose.yml").is_file():
+            load_env_file(deploy_root / ".env")
+    if len(script.parents) >= 2:
+        load_env_file(script.parents[1] / ".env")
+
+
+def sync_pg_env_from_db_vars() -> None:
+    if not os.environ.get("PGUSER") and os.environ.get("DB_USER"):
+        os.environ["PGUSER"] = os.environ["DB_USER"]
+    if not os.environ.get("PGPASSWORD") and os.environ.get("DB_PASSWORD"):
+        os.environ["PGPASSWORD"] = os.environ["DB_PASSWORD"]
+    if not os.environ.get("PGDATABASE"):
+        os.environ["PGDATABASE"] = "ems"
+
+
 def load_prices_csv(path: str) -> list[tuple[datetime, float]]:
     out: list[tuple[datetime, float]] = []
     with open(path, newline="", encoding="utf-8") as f:
@@ -118,13 +162,23 @@ def load_prices_db(date_from: date, date_to: date) -> list[tuple[datetime, float
     t0 = datetime.combine(date_from, datetime.min.time(), tzinfo=prg).astimezone(timezone.utc)
     t1 = datetime.combine(date_to, datetime.min.time(), tzinfo=prg).astimezone(timezone.utc)
 
-    conn = psycopg2.connect(
-        host=os.environ.get("PGHOST", "127.0.0.1"),
-        port=int(os.environ.get("PGPORT", "5432")),
-        dbname=os.environ.get("PGDATABASE", "ems"),
-        user=os.environ.get("PGUSER", os.environ.get("DB_USER", "ems_user")),
-        password=os.environ.get("PGPASSWORD", os.environ.get("DB_PASSWORD", "")),
+    dsn = (
+        os.environ.get("DATABASE_URL")
+        or os.environ.get("EMS_DATABASE_URL")
+        or os.environ.get("POSTGRES_URL")
     )
+    if dsn:
+        if dsn.startswith("postgres://"):
+            dsn = "postgresql://" + dsn[len("postgres://") :]
+        conn = psycopg2.connect(dsn)
+    else:
+        conn = psycopg2.connect(
+            host=os.environ.get("PGHOST", "127.0.0.1"),
+            port=int(os.environ.get("PGPORT", "5432")),
+            dbname=os.environ.get("PGDATABASE", "ems"),
+            user=os.environ.get("PGUSER", os.environ.get("DB_USER", "ems_user")),
+            password=os.environ.get("PGPASSWORD", os.environ.get("DB_PASSWORD", "")),
+        )
     cur = conn.cursor()
     cur.execute(
         """
@@ -270,7 +324,19 @@ def simulate_year(
 
 def main() -> None:
     ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
-    ap.add_argument("--db", action="store_true", help="Načti OTE z Postgres (env PG* / DB_*)")
+    ap.add_argument("--db", action="store_true", help="Načti OTE z Postgres (env PG* / DB_* / DATABASE_URL)")
+    ap.add_argument(
+        "--no-auto-env",
+        action="store_true",
+        help="Nenačítej automaticky .env z ems-deploy/ ani app/",
+    )
+    ap.add_argument("--env-file", type=str, default="", help="Dodatečný soubor .env (po auto-env)")
+    ap.add_argument(
+        "--pg-host",
+        type=str,
+        default="",
+        help="Přepíše PGHOST (např. stejná IP jako EMS_DB_BIND ve compose)",
+    )
     ap.add_argument("--price-csv", type=str, default="", help="CSV: interval_start, sell_raw_price_czk_kwh")
     ap.add_argument("--date-from", type=str, required=True)
     ap.add_argument("--date-to", type=str, required=True)
@@ -291,6 +357,13 @@ def main() -> None:
     d0 = date.fromisoformat(args.date_from)
     d1 = date.fromisoformat(args.date_to)
     if args.db:
+        if not args.no_auto_env:
+            apply_auto_env_files()
+        if args.env_file:
+            load_env_file(Path(args.env_file))
+        sync_pg_env_from_db_vars()
+        if args.pg_host:
+            os.environ["PGHOST"] = args.pg_host
         series = load_prices_db(d0, d1)
     elif args.price_csv:
         series = load_prices_csv(args.price_csv)