diff --git a/custom_components/checkwatt/__init__.py b/custom_components/checkwatt/__init__.py
index 0865908..c0ff685 100644
--- a/custom_components/checkwatt/__init__.py
+++ b/custom_components/checkwatt/__init__.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import json
 import logging
 from datetime import UTC, date, datetime, timedelta
 from zoneinfo import ZoneInfo
@@ -15,6 +16,7 @@
 
 from .api import AuthenticationError, CheckwattApiClient
 from .const import (
+    DIAG_UPDATE_INTERVAL,
     DOMAIN,
     ENERGY_UPDATE_INTERVAL,
     LOGBOOK_UPDATE_INTERVAL,
@@ -50,6 +52,43 @@ def _select_spot_price(prices: list[dict], now_local: datetime) -> float | None:
     return current
 
 
+def _parse_diag_blob(blob: dict) -> dict:
+    """Extract HA-relevant values from a connectionStatus Current.Blob.
+
+    Battery temperatures come from the inverter stats; with several inverters
+    the highest high and lowest low are reported, matching the EIB UI.
+    """
+    temps_h: list[float] = []
+    temps_l: list[float] = []
+    inverter_stats = (blob.get("topics") or {}).get("ems/inverter_stat") or {}
+    for inverters in inverter_stats.values():
+        if not isinstance(inverters, list):
+            continue
+        for inv in inverters:
+            if not isinstance(inv, dict):
+                continue
+            if inv.get("temp_h") is not None:
+                temps_h.append(inv["temp_h"])
+            if inv.get("temp_l") is not None:
+                temps_l.append(inv["temp_l"])
+
+    default_route = blob.get("default_route") or []
+    if blob.get("hello_eth0"):
+        connection = "Network cable (LAN1)"
+    elif "ppp0" in default_route:
+        connection = "Mobile internet (4G)"
+    else:
+        connection = "No internet"
+
+    return {
+        "battery_temp_high_c": max(temps_h) if temps_h else None,
+        "battery_temp_low_c": min(temps_l) if temps_l else None,
+        "internet_connection": connection,
+        "cm10_uptime_s": blob.get("uptime_s"),
+        "default_route": default_route,
+    }
+
+
 async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Set up CheckWatt from a config entry."""
     # H2: dedicated session with explicit SSL verification.
@@ -121,6 +160,7 @@ def __init__(
         self._last_price_update: datetime | None = None
         self._last_energy_update: datetime | None = None
         self._last_logbook_update: datetime | None = None
+        self._last_diag_update: datetime | None = None
         self._last_news_update: datetime | None = None
         self._last_news_ts: str | None = None
 
@@ -156,6 +196,12 @@ async def _async_update_data(self) -> dict:
             if new_test_status is not None:
                 self._last_test_status = new_test_status
 
+            # Available power the battery can offer CheckWatt right now
+            # (the EIB "Available power" panel).
+            related_meters = {
+                m.get("Type"): m.get("PeakAcKw") for m in status.get("RelatedMeters") or []
+            }
+
             data: dict = {
                 # Identity
                 "site_id": self._site_id,
@@ -172,6 +218,8 @@ async def _async_update_data(self) -> dict:
                 "operation_preference": status.get("OperationPreference"),
                 "fp_up_kw": status.get("FpUpInKw"),
                 "fp_down_kw": status.get("FpDownInKw"),
+                "available_charge_kw": related_meters.get("Charging"),
+                "available_discharge_kw": related_meters.get("Discharging"),
                 "test_info": test_info,
                 "logbook_raw": self._logbook_raw,
                 # Event signals — reset each cycle, set below if triggered.
@@ -201,6 +249,10 @@ async def _async_update_data(self) -> dict:
                 await self._update_logbook(data)
                 self._last_logbook_update = now
 
+            if self._due(self._last_diag_update, DIAG_UPDATE_INTERVAL):
+                await self._update_diagnostics(data)
+                self._last_diag_update = now
+
             if self._due(self._last_news_update, NEWS_UPDATE_INTERVAL):
                 await self._update_news(data)
                 self._last_news_update = now
@@ -281,6 +333,11 @@ def _slow_data(self) -> dict:
                 "total_export_kwh": None,
                 "total_charge_kwh": None,
                 "total_discharge_kwh": None,
+                "battery_temp_high_c": None,
+                "battery_temp_low_c": None,
+                "internet_connection": None,
+                "cm10_uptime_s": None,
+                "default_route": None,
             }
         # Note: event signals (cm10_status_changed, new_logbook_entries) are
         # intentionally NOT carried over — they must only fire once per occurrence.
@@ -296,6 +353,11 @@ def _slow_data(self) -> dict:
                 "total_export_kwh",
                 "total_charge_kwh",
                 "total_discharge_kwh",
+                "battery_temp_high_c",
+                "battery_temp_low_c",
+                "internet_connection",
+                "cm10_uptime_s",
+                "default_route",
             )
         }
 
@@ -369,6 +431,19 @@ async def _update_logbook(self, data: dict) -> None:
         except Exception as err:
             _LOGGER.warning("Logbook update failed (%s): %s", type(err).__name__, err)
 
+    async def _update_diagnostics(self, data: dict) -> None:
+        """Fetch CM10 diagnostics: battery temperatures and internet connection."""
+        try:
+            resp = await self._client.get_connection_status(self._site_id)
+            blob_raw = (resp.get("Current") or {}).get("Blob")
+            if not blob_raw:
+                return
+            blob = json.loads(blob_raw)
+            if isinstance(blob, dict):
+                data.update(_parse_diag_blob(blob))
+        except Exception as err:
+            _LOGGER.warning("Diagnostics update failed (%s): %s", type(err).__name__, err)
+
     async def _update_news(self, data: dict) -> None:
         """Fetch news and detect items published since the last check."""
         try:
diff --git a/custom_components/checkwatt/api.py b/custom_components/checkwatt/api.py
index 02038e2..8c8d48a 100644
--- a/custom_components/checkwatt/api.py
+++ b/custom_components/checkwatt/api.py
@@ -225,6 +225,23 @@ async def get_news(self) -> list:
         except (ClientResponseError, ClientError) as err:
             raise ConnectionError(f"News request failed: {type(err).__name__}") from err
 
+    async def get_connection_status(self, site_id: int) -> dict:
+        """Fetch CM10 diagnostics: connectivity, uptime and inverter temperatures.
+
+        New endpoint 2026-09, backs the EIB "Internet connection" and
+        "Battery temperature" panels. The interesting data lives in
+        Current.Blob, a JSON-encoded string.
+        """
+        now = datetime.now(UTC)
+        fmt = "%Y-%m-%dT%H:%M:%S.000Z"
+        return await self._get(
+            f"/diag/{site_id}/connectionStatus",
+            params={
+                "from": (now - timedelta(minutes=5)).strftime(fmt),
+                "to": now.strftime(fmt),
+            },
+        )
+
     async def get_energy_totals(self, meter_ids: list[int]) -> dict:
         """Fetch all-time yearly-grouped totals for the given meter IDs."""
         from datetime import date
diff --git a/custom_components/checkwatt/const.py b/custom_components/checkwatt/const.py
index 700c2f8..45538ec 100644
--- a/custom_components/checkwatt/const.py
+++ b/custom_components/checkwatt/const.py
@@ -12,4 +12,5 @@
 PRICE_UPDATE_INTERVAL = timedelta(minutes=60)
 ENERGY_UPDATE_INTERVAL = timedelta(minutes=15)
 LOGBOOK_UPDATE_INTERVAL = timedelta(minutes=30)
+DIAG_UPDATE_INTERVAL = timedelta(minutes=5)
 NEWS_UPDATE_INTERVAL = timedelta(hours=4)
diff --git a/custom_components/checkwatt/manifest.json b/custom_components/checkwatt/manifest.json
index e706170..6fd31e7 100644
--- a/custom_components/checkwatt/manifest.json
+++ b/custom_components/checkwatt/manifest.json
@@ -1,7 +1,7 @@
 {
   "domain": "checkwatt",
   "name": "CheckWatt",
-  "version": "1.4.3",
+  "version": "1.5.0",
   "documentation": "https://github.com/andreasthell/ha-cw",
   "issue_tracker": "https://github.com/andreasthell/ha-cw/issues",
   "codeowners": ["@andreasthell"],
diff --git a/custom_components/checkwatt/sensor.py b/custom_components/checkwatt/sensor.py
index 29624ae..bb82e67 100644
--- a/custom_components/checkwatt/sensor.py
+++ b/custom_components/checkwatt/sensor.py
@@ -18,6 +18,7 @@
     PERCENTAGE,
     UnitOfEnergy,
     UnitOfPower,
+    UnitOfTemperature,
 )
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.device_registry import DeviceInfo
@@ -164,6 +165,44 @@ def _parse_dt(value: str | None) -> datetime | None:
         suggested_display_precision=0,
         value_fn=lambda d: d.get("battery_soc_pct"),
     ),
+    # ---- Available power (EIB "Available power" panel) ----------------------
+    CheckwattSensorDescription(
+        key="available_charge_kw",
+        translation_key="available_charge_power",
+        device_class=SensorDeviceClass.POWER,
+        state_class=SensorStateClass.MEASUREMENT,
+        native_unit_of_measurement=UnitOfPower.KILO_WATT,
+        suggested_display_precision=1,
+        value_fn=lambda d: d.get("available_charge_kw"),
+    ),
+    CheckwattSensorDescription(
+        key="available_discharge_kw",
+        translation_key="available_discharge_power",
+        device_class=SensorDeviceClass.POWER,
+        state_class=SensorStateClass.MEASUREMENT,
+        native_unit_of_measurement=UnitOfPower.KILO_WATT,
+        suggested_display_precision=1,
+        value_fn=lambda d: d.get("available_discharge_kw"),
+    ),
+    # ---- Battery temperature ------------------------------------------------
+    CheckwattSensorDescription(
+        key="battery_temp_high_c",
+        translation_key="battery_temp_high",
+        device_class=SensorDeviceClass.TEMPERATURE,
+        state_class=SensorStateClass.MEASUREMENT,
+        native_unit_of_measurement=UnitOfTemperature.CELSIUS,
+        suggested_display_precision=1,
+        value_fn=lambda d: d.get("battery_temp_high_c"),
+    ),
+    CheckwattSensorDescription(
+        key="battery_temp_low_c",
+        translation_key="battery_temp_low",
+        device_class=SensorDeviceClass.TEMPERATURE,
+        state_class=SensorStateClass.MEASUREMENT,
+        native_unit_of_measurement=UnitOfTemperature.CELSIUS,
+        suggested_display_precision=1,
+        value_fn=lambda d: d.get("battery_temp_low_c"),
+    ),
     # ---- Revenue ------------------------------------------------------------
     CheckwattSensorDescription(
         key="today_revenue_sek",
@@ -293,6 +332,12 @@ def _parse_dt(value: str | None) -> datetime | None:
         icon="mdi:notebook-outline",
         value_fn=lambda d: _logbook_state(d.get("logbook_raw")),
     ),
+    CheckwattSensorDescription(
+        key="internet_connection",
+        translation_key="internet_connection",
+        icon="mdi:lan",
+        value_fn=lambda d: d.get("internet_connection"),
+    ),
     CheckwattSensorDescription(
         key="firmware_version",
         translation_key="firmware_version",
@@ -366,4 +411,9 @@ def extra_state_attributes(self) -> dict | None:
                 for e in entries[:5]
             ]
             return {"recent_entries": recent}
+        if key == "internet_connection":
+            return {
+                "uptime_s": self.coordinator.data.get("cm10_uptime_s"),
+                "default_route": self.coordinator.data.get("default_route"),
+            }
         return None
diff --git a/custom_components/checkwatt/strings.json b/custom_components/checkwatt/strings.json
index e20a331..2657857 100644
--- a/custom_components/checkwatt/strings.json
+++ b/custom_components/checkwatt/strings.json
@@ -44,6 +44,11 @@
       "total_grid_export": {"name": "Total Grid Export"},
       "total_battery_charge": {"name": "Total Battery Charge"},
       "total_battery_discharge": {"name": "Total Battery Discharge"},
+      "available_charge_power": {"name": "Available Charge Power"},
+      "available_discharge_power": {"name": "Available Discharge Power"},
+      "battery_temp_high": {"name": "Battery Temperature High"},
+      "battery_temp_low": {"name": "Battery Temperature Low"},
+      "internet_connection": {"name": "Internet Connection"},
       "cm10_status": {"name": "CM10 Status"},
       "last_seen_cm10": {"name": "CM10 Last Seen"},
       "last_seen_inverter": {"name": "Inverter Last Seen"},
diff --git a/custom_components/checkwatt/translations/en.json b/custom_components/checkwatt/translations/en.json
index e20a331..2657857 100644
--- a/custom_components/checkwatt/translations/en.json
+++ b/custom_components/checkwatt/translations/en.json
@@ -44,6 +44,11 @@
       "total_grid_export": {"name": "Total Grid Export"},
       "total_battery_charge": {"name": "Total Battery Charge"},
       "total_battery_discharge": {"name": "Total Battery Discharge"},
+      "available_charge_power": {"name": "Available Charge Power"},
+      "available_discharge_power": {"name": "Available Discharge Power"},
+      "battery_temp_high": {"name": "Battery Temperature High"},
+      "battery_temp_low": {"name": "Battery Temperature Low"},
+      "internet_connection": {"name": "Internet Connection"},
       "cm10_status": {"name": "CM10 Status"},
       "last_seen_cm10": {"name": "CM10 Last Seen"},
       "last_seen_inverter": {"name": "Inverter Last Seen"},
diff --git a/custom_components/checkwatt/translations/sv.json b/custom_components/checkwatt/translations/sv.json
index 8aa9e17..465674f 100644
--- a/custom_components/checkwatt/translations/sv.json
+++ b/custom_components/checkwatt/translations/sv.json
@@ -44,6 +44,11 @@
       "total_grid_export": {"name": "Total nätexport"},
       "total_battery_charge": {"name": "Total batteriladdning"},
       "total_battery_discharge": {"name": "Total batteriurladdning"},
+      "available_charge_power": {"name": "Tillgänglig laddeffekt"},
+      "available_discharge_power": {"name": "Tillgänglig urladdningseffekt"},
+      "battery_temp_high": {"name": "Batteritemperatur högsta"},
+      "battery_temp_low": {"name": "Batteritemperatur lägsta"},
+      "internet_connection": {"name": "Internetanslutning"},
       "cm10_status": {"name": "CM10 Status"},
       "last_seen_cm10": {"name": "CM10 senast sedd"},
       "last_seen_inverter": {"name": "Växelriktare senast sedd"},
diff --git a/docs/api.md b/docs/api.md
index e33e688..d74c074 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -825,6 +825,78 @@ Returns pending EMS configuration changes. Response is an array of service strin
 
 ---
 
+## Diagnostics
+
+### Get connection status (new 2026-09)
+
+```
+GET /diag/{site_id}/connectionStatus?from={iso_utc}&to={iso_utc}
+Authorization: Bearer {jwt_token}
+```
+
+Backs the EIB "Internet connection" and "Battery temperature" panels. The web
+app queries a 5-minute window ending now (ISO 8601 UTC with milliseconds, e.g.
+`2026-09-16T09:20:46.097Z`).
+
+**Response 200:**
+```json
+{
+  "SiteId": 12345,
+  "From": "2026-09-16T09:20:46.097Z",
+  "To": "2026-09-16T09:25:46.097Z",
+  "Current": {"Timestamp": "2026-09-16T08:13:35Z", "Blob": "{...json string...}"},
+  "History": []
+}
+```
+
+`Current.Blob` is a **JSON-encoded string** with CM10 diagnostics:
+
+```json
+{
+  "eth": {"eth0": {"rx_packets": 4527, "carrier_changes": 0}, "eth1": {}, "win_s": 4197},
+  "topics": {
+    "ems/inverter_stat": {
+      "goodwe": [
+        {
+          "id": "192.168.5.128",
+          "soc": 85.0,
+          "model": "GW10KN-ET",
+          "serial": "...",
+          "fw_ver": "master:13-slave:13 /arm:33",
+          "temp_h": 36.4,
+          "temp_l": 20.8,
+          "pv_power": 0.0,
+          "battery_power": -12.0,
+          "set_point": 0.0
+        }
+      ]
+    },
+    "ems/datastream_energyPv": 0.0,
+    "ems/datastream_energyImport": 186.0,
+    "ems/datastream_energyDischarge": -12.0
+  },
+  "screens": ["15814.sender", "15811.goodwe", "..."],
+  "arp_eth1": [{"ip": "192.168.5.128", "mac": "...", "state": ["REACHABLE"]}],
+  "uptime_s": 1114187,
+  "linux_ips": [{"ip": "...", "iface": "eth0"}],
+  "hello_eth0": true,
+  "modem_stat": {"ts": "2026-09-16 04:05:04", "status": "modem"},
+  "default_route": ["ppp0", "eth0"]
+}
+```
+
+Key fields:
+- `topics."ems/inverter_stat".{vendor}[].temp_h` / `temp_l` – battery temperature highest/lowest (°C)
+- `hello_eth0` – LAN1 internet check succeeded (EIB shows "Primary – Network cable (LAN1): Connected")
+- `default_route` – active route interfaces (`eth0` = LAN1, `ppp0` = 4G modem)
+- `uptime_s` – CM10 uptime in seconds
+- `eth1` / `arp_eth1` – the inverter-facing LAN port
+
+The "Available power" panel (Can charge / Can discharge) comes from
+`RelatedMeters[].PeakAcKw` in `/site/Statuses`, not from this endpoint.
+
+---
+
 ## Misc
 
 ### Get energy providers list
@@ -849,6 +921,7 @@ No auth required. Returns all energy retailers across SE/NO/DK/FI with Id and Di
 | Monthly revenue | 15 min | `/revenue/{siteId}` |
 | Spot price | 60 min (or at :00 when tomorrow's prices arrive ~13:00) | `/ems/spotprice` |
 | Site status / CM10 seen | 5 min | `/site/Statuses` |
+| Diagnostics (battery temp, connectivity) | 5 min | `/diag/{siteId}/connectionStatus` |
 | Site details / tariff | On setup + daily | `/site/{siteId}`, `/Tariff/{id}` |
 
 ### Token lifecycle
diff --git a/tests/conftest.py b/tests/conftest.py
index 23b36eb..ea30359 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -60,6 +60,7 @@ def _enum_stub(name: str, *values: str):
         "MONETARY",
         "ENERGY",
         "TIMESTAMP",
+        "TEMPERATURE",
     ),
     SensorEntity=object,
     SensorEntityDescription=_SensorEntityDescription,
@@ -70,7 +71,8 @@ def _enum_stub(name: str, *values: str):
     "homeassistant.const",
     PERCENTAGE="PERCENTAGE",
     UnitOfEnergy=type("UnitOfEnergy", (), {"KILO_WATT_HOUR": "kWh"}),
-    UnitOfPower=type("UnitOfPower", (), {"WATT": "W"}),
+    UnitOfPower=type("UnitOfPower", (), {"WATT": "W", "KILO_WATT": "kW"}),
+    UnitOfTemperature=type("UnitOfTemperature", (), {"CELSIUS": "°C"}),
     CONF_USERNAME="username",
     CONF_PASSWORD="password",
     Platform=type("Platform", (), {"SENSOR": "sensor", "EVENT": "event"}),
diff --git a/tests/test_diagnostics.py b/tests/test_diagnostics.py
new file mode 100644
index 0000000..b455940
--- /dev/null
+++ b/tests/test_diagnostics.py
@@ -0,0 +1,85 @@
+"""Tests for connectionStatus diagnostics blob parsing."""
+
+from custom_components.checkwatt import _parse_diag_blob
+
+
+def _blob(**overrides) -> dict:
+    """A realistic Current.Blob dict, shaped like the 2026-09 API response."""
+    blob = {
+        "eth": {"eth0": {"rx_packets": 4527}, "eth1": {"rx_packets": 61803}},
+        "topics": {
+            "ems/inverter_stat": {
+                "goodwe": [
+                    {
+                        "id": "192.168.5.128",
+                        "soc": 85.0,
+                        "model": "GW10KN-ET ",
+                        "temp_h": 36.4,
+                        "temp_l": 20.8,
+                        "pv_power": 0.0,
+                        "battery_power": -12.0,
+                    }
+                ]
+            },
+            "ems/datastream_energyPv": 0.0,
+        },
+        "uptime_s": 1114187,
+        "hello_eth0": True,
+        "modem_stat": {"ts": "2026-09-16 04:05:04", "status": "modem"},
+        "default_route": ["ppp0", "eth0"],
+    }
+    blob.update(overrides)
+    return blob
+
+
+class TestParseDiagBlob:
+    def test_battery_temperatures(self):
+        result = _parse_diag_blob(_blob())
+        assert result["battery_temp_high_c"] == 36.4
+        assert result["battery_temp_low_c"] == 20.8
+
+    def test_multiple_inverters_take_extremes(self):
+        blob = _blob()
+        blob["topics"]["ems/inverter_stat"]["goodwe"].append({"temp_h": 40.1, "temp_l": 25.0})
+        result = _parse_diag_blob(blob)
+        assert result["battery_temp_high_c"] == 40.1
+        assert result["battery_temp_low_c"] == 20.8
+
+    def test_no_inverter_stats(self):
+        result = _parse_diag_blob(_blob(topics={}))
+        assert result["battery_temp_high_c"] is None
+        assert result["battery_temp_low_c"] is None
+
+    def test_missing_temps_ignored(self):
+        blob = _blob()
+        blob["topics"]["ems/inverter_stat"]["goodwe"] = [{"temp_h": None, "temp_l": None}]
+        result = _parse_diag_blob(blob)
+        assert result["battery_temp_high_c"] is None
+        assert result["battery_temp_low_c"] is None
+
+    def test_lan_connected(self):
+        result = _parse_diag_blob(_blob())
+        assert result["internet_connection"] == "Network cable (LAN1)"
+
+    def test_modem_fallback(self):
+        result = _parse_diag_blob(_blob(hello_eth0=False))
+        assert result["internet_connection"] == "Mobile internet (4G)"
+
+    def test_no_internet(self):
+        result = _parse_diag_blob(_blob(hello_eth0=False, default_route=["eth0"]))
+        assert result["internet_connection"] == "No internet"
+
+    def test_no_internet_when_routes_missing(self):
+        result = _parse_diag_blob(_blob(hello_eth0=False, default_route=None))
+        assert result["internet_connection"] == "No internet"
+
+    def test_uptime_and_routes(self):
+        result = _parse_diag_blob(_blob())
+        assert result["cm10_uptime_s"] == 1114187
+        assert result["default_route"] == ["ppp0", "eth0"]
+
+    def test_empty_blob(self):
+        result = _parse_diag_blob({})
+        assert result["battery_temp_high_c"] is None
+        assert result["internet_connection"] == "No internet"
+        assert result["cm10_uptime_s"] is None