diff --git a/app.py b/app.py
index 1f2d21d..16054c0 100644
--- a/app.py
+++ b/app.py
@@ -1,4 +1,4 @@
-from flask import Flask, render_template, redirect, url_for, request, flash, abort, send_from_directory
+from flask import Flask, render_template, redirect, url_for, request, flash, abort, send_from_directory, jsonify
 from sqlalchemy import create_engine, func
 from sqlalchemy.orm import scoped_session, sessionmaker
 
@@ -547,6 +547,12 @@ def create_app(config_object="config"):
     # Devices — list
     # ------------------------------------------------------------------ #
 
+    @app.route("/ha/entities")
+    def ha_entities():
+        if not ha_client.enabled:
+            return jsonify([])
+        return jsonify(ha_client.list_battery_entities())
+
     @app.route("/device/")
     def device_list():
         devices = db.query(Device).order_by(Device.name).all()
@@ -614,10 +620,28 @@ def create_app(config_object="config"):
             .filter_by(status="available")
             .order_by(Battery.label).all())
         device_types = sorted({d.device_type for d in db.query(Device).all() if d.device_type})
+        ha_live_pct = None
+        if ha_client.enabled and device.ha_entity_id:
+            ha_live_pct = ha_client.get_state(device.ha_entity_id, timeout=4)
+            if ha_live_pct is not None:
+                changed = False
+                for battery in device.batteries:
+                    if battery.status == "installed" and battery.battery_percentage != ha_live_pct:
+                        battery.battery_percentage = ha_live_pct
+                        db.add(BatteryPctLog(
+                            battery_id=battery.id,
+                            percentage=ha_live_pct,
+                            recorded_at=datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"),
+                            source="poll",
+                        ))
+                        changed = True
+                if changed:
+                    db.commit()
         return render_template("device_detail.html", device=device, brands=brands,
                                available_batteries=available_batteries,
                                device_types=device_types,
-                               ha_enabled=ha_client.enabled)
+                               ha_enabled=ha_client.enabled,
+                               ha_live_pct=ha_live_pct)
 
     # ------------------------------------------------------------------ #
     # Devices — edit
diff --git a/ha_client.py b/ha_client.py
index 0db568e..620ad53 100644
--- a/ha_client.py
+++ b/ha_client.py
@@ -21,7 +21,7 @@ class HomeAssistantClient:
     def enabled(self) -> bool:
         return self._enabled
 
-    def get_state(self, entity_id: str) -> int | None:
+    def get_state(self, entity_id: str, timeout: int = 10) -> int | None:
         """Fetch the current state of a HA entity and return it as an integer.
 
         Returns None if HA is not configured, the entity is not found,
@@ -31,10 +31,37 @@ class HomeAssistantClient:
             return None
         url = f"{self._base_url}/api/states/{entity_id}"
         try:
-            resp = requests.get(url, headers=self._headers, timeout=10)
+            resp = requests.get(url, headers=self._headers, timeout=timeout)
             resp.raise_for_status()
             state = resp.json().get("state")
             return int(float(state))
         except (requests.RequestException, ValueError, TypeError, KeyError) as exc:
             logger.warning("HA API error for %s: %s", entity_id, exc)
             return None
+
+    def list_battery_entities(self) -> list[dict]:
+        """Return all HA entities that look like battery sensors.
+
+        Includes entities where device_class == 'battery' or 'battery' appears
+        in the entity_id. Returns [] when disabled or on any error.
+        """
+        if not self._enabled:
+            return []
+        url = f"{self._base_url}/api/states"
+        try:
+            resp = requests.get(url, headers=self._headers, timeout=15)
+            resp.raise_for_status()
+            result = []
+            for s in resp.json():
+                eid = s.get("entity_id", "")
+                attrs = s.get("attributes", {})
+                if (attrs.get("device_class") == "battery"
+                        or "battery" in eid.lower()):
+                    result.append({
+                        "entity_id": eid,
+                        "friendly_name": attrs.get("friendly_name", eid),
+                    })
+            return sorted(result, key=lambda x: x["entity_id"])
+        except (requests.RequestException, ValueError, TypeError) as exc:
+            logger.warning("HA list_battery_entities error: %s", exc)
+            return []
diff --git a/templates/device_detail.html b/templates/device_detail.html
index 331bd48..c2293de 100644
--- a/templates/device_detail.html
+++ b/templates/device_detail.html
@@ -31,8 +31,20 @@
     {% if ha_enabled and device.ha_entity_id %}
     <tr>
       <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">HA Entity</td>
-      <td style="border:none;"><code>{{ device.ha_entity_id }}</code></td>
+      <td style="border:none;"><code style="word-break:break-all;">{{ device.ha_entity_id }}</code></td>
     </tr>
+    {% if ha_live_pct is not none %}
+    <tr>
+      <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">HA Live %</td>
+      <td style="border:none;">
+        {% if ha_live_pct < 20 %}
+          <span class="badge badge-warning">⚠ {{ ha_live_pct }}%</span>
+        {% else %}
+          {{ ha_live_pct }}%
+        {% endif %}
+      </td>
+    </tr>
+    {% endif %}
     {% endif %}
   </table>
 </div>
@@ -200,7 +212,10 @@ function addInstallRow() {
       <label for="edit-ha-entity">Home Assistant Entity ID</label>
       <input type="text" id="edit-ha-entity" name="ha_entity_id"
              value="{{ device.ha_entity_id or '' }}"
-             placeholder="e.g. sensor.tv_remote_battery">
+             placeholder="e.g. sensor.tv_remote_battery"
+             list="ha-entities-list" autocomplete="off">
+      <datalist id="ha-entities-list"></datalist>
+      <small class="text-muted" id="ha-entities-status" style="display:block;margin-top:0.25rem;font-size:0.8rem;"></small>
     </div>
     {% endif %}
     <button class="btn btn-primary" type="submit">Save Changes</button>
@@ -218,4 +233,39 @@ function addInstallRow() {
 </div>
 
 <a class="text-muted" href="{{ url_for('device_list') }}">&larr; Back to Devices</a>
+
+{% if ha_enabled %}
+<script>
+(function() {
+  var datalist = document.getElementById('ha-entities-list');
+  var status   = document.getElementById('ha-entities-status');
+  if (!datalist) return;
+
+  function populate(entities) {
+    datalist.innerHTML = '';
+    entities.forEach(function(e) {
+      var opt = document.createElement('option');
+      opt.value = e.entity_id;
+      if (e.friendly_name && e.friendly_name !== e.entity_id) opt.label = e.friendly_name;
+      datalist.appendChild(opt);
+    });
+    if (status) status.textContent = entities.length ? entities.length + ' battery entities available' : '';
+  }
+
+  try {
+    var cached = sessionStorage.getItem('ha_battery_entities');
+    if (cached) { populate(JSON.parse(cached)); return; }
+  } catch(e) {}
+
+  if (status) status.textContent = 'Loading HA entities\u2026';
+  fetch('/ha/entities')
+    .then(function(r) { return r.json(); })
+    .then(function(entities) {
+      try { sessionStorage.setItem('ha_battery_entities', JSON.stringify(entities)); } catch(e) {}
+      populate(entities);
+    })
+    .catch(function() { if (status) status.textContent = ''; });
+}());
+</script>
+{% endif %}
 {% endblock %}
diff --git a/tests/test_ha_integration.py b/tests/test_ha_integration.py
index 34a6605..5a903c3 100644
--- a/tests/test_ha_integration.py
+++ b/tests/test_ha_integration.py
@@ -470,3 +470,80 @@ def test_manual_edit_no_log_when_unchanged(ha_client_f):
     resp = ha_client_f.get("/battery/1")
     # "40%" appears once in the info section and once in history — not twice in history
     assert resp.data.count(b"40%") == 2
+
+
+# ---------------------------------------------------------------------------
+# Group 5 — live fetch on device page load + /ha/entities endpoint
+# ---------------------------------------------------------------------------
+
+def test_device_detail_shows_live_pct(ha_app, ha_client_f):
+    """Opening a device page fetches live % from HA and displays it."""
+    ha_client_f.post("/device/add", data={"name": "Dev Live", "battery_slots": "1"})
+    ha_client_f.post("/device/1/edit", data={
+        "name": "Dev Live", "battery_slots": "1", "ha_entity_id": "sensor.live_test"
+    })
+
+    mock_resp = MagicMock()
+    mock_resp.json.return_value = {"state": "78", "entity_id": "sensor.live_test"}
+    mock_resp.raise_for_status.return_value = None
+
+    with patch("ha_client.requests.get", return_value=mock_resp):
+        resp = ha_client_f.get("/device/1")
+
+    assert resp.status_code == 200
+    assert b"78%" in resp.data
+
+
+def test_device_detail_updates_battery_on_load(ha_app, ha_client_f):
+    """Battery percentage is updated (with pct_log) when device page is loaded and value changed."""
+    ha_client_f.post("/device/add", data={"name": "Dev Update", "battery_slots": "1"})
+    ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
+    ha_client_f.post("/battery/1/assign", data={"device_id": "1"})
+    ha_client_f.post("/device/1/edit", data={
+        "name": "Dev Update", "battery_slots": "1", "ha_entity_id": "sensor.update_test"
+    })
+
+    mock_resp = MagicMock()
+    mock_resp.json.return_value = {"state": "63"}
+    mock_resp.raise_for_status.return_value = None
+
+    with patch("ha_client.requests.get", return_value=mock_resp):
+        ha_client_f.get("/device/1")
+
+    from sqlalchemy import create_engine
+    from sqlalchemy.orm import sessionmaker
+    from models import Battery, BatteryPctLog
+    engine = create_engine(ha_app.config["SQLALCHEMY_DATABASE_URI"])
+    s = sessionmaker(bind=engine)()
+    b = s.get(Battery, 1)
+    assert b.battery_percentage == 63
+    logs = s.query(BatteryPctLog).filter_by(battery_id=1, source="poll").all()
+    assert len(logs) == 1
+    assert logs[0].percentage == 63
+    s.close()
+
+
+def test_ha_entities_endpoint(ha_app, ha_client_f):
+    """GET /ha/entities returns only battery-related entities from HA."""
+    mock_resp = MagicMock()
+    mock_resp.json.return_value = [
+        {"entity_id": "sensor.tv_battery",    "attributes": {"device_class": "battery", "friendly_name": "TV Battery"}},
+        {"entity_id": "sensor.remote_battery", "attributes": {"friendly_name": "Remote"}},  # 'battery' in id
+        {"entity_id": "sensor.temperature",   "attributes": {"device_class": "temperature", "friendly_name": "Temp"}},
+        {"entity_id": "light.living_room",     "attributes": {}},
+    ]
+    mock_resp.raise_for_status.return_value = None
+
+    with patch("ha_client.requests.get", return_value=mock_resp):
+        resp = ha_client_f.get("/ha/entities")
+
+    assert resp.status_code == 200
+    data = resp.get_json()
+    entity_ids = [e["entity_id"] for e in data]
+    assert "sensor.tv_battery" in entity_ids
+    assert "sensor.remote_battery" in entity_ids
+    assert "sensor.temperature" not in entity_ids
+    assert "light.living_room" not in entity_ids
+    # friendly names present
+    tv = next(e for e in data if e["entity_id"] == "sensor.tv_battery")
+    assert tv["friendly_name"] == "TV Battery"