diff --git a/SolixBLE/__init__.py b/SolixBLE/__init__.py
index 7e30d6b..f43b0ab 100644
--- a/SolixBLE/__init__.py
+++ b/SolixBLE/__init__.py
@@ -7,6 +7,7 @@
 from .device import SolixBLEDevice
 from .devices import (
     C300,
+    C200DC,
     C300DC,
     C800,
     C1000,
@@ -31,6 +32,7 @@
 __all__ = [
     "SolixBLEDevice",
     "C300",
+    "C200DC",
     "C300DC",
     "C800",
     "C1000",
diff --git a/SolixBLE/device.py b/SolixBLE/device.py
index a563ad9..3ccbee5 100644
--- a/SolixBLE/device.py
+++ b/SolixBLE/device.py
@@ -75,6 +75,7 @@ def __init__(self, ble_device: BLEDevice) -> None:
         self._connection_attempts: int = 0
         self._shared_key: bytes | None = None
         self._iv: bytes | None = None
+        self._unencrypted_session: bool = False
 
     def add_callback(self, function: Callable[[], None]) -> None:
         """Register a callback to be run on state updates.
@@ -249,8 +250,10 @@ def negotiated(self) -> bool:
         """
         return (
             self.connected
-            and self._shared_key is not None
-            and self._iv is not None
+            and (
+                (self._shared_key is not None and self._iv is not None)
+                or self._unencrypted_session
+            )
             and self._negotiation_timestamp is not None
         )
 
@@ -573,6 +576,12 @@ async def _process_notification(
                         parameters = self._parse_payload(decrypted_payload)
                         return await self._process_telemetry(cmd, parameters)
 
+                    # C200 DC telemetry appears to be sent unencrypted on 0402.
+                    case "0402":
+                        _LOGGER.debug("Received plaintext telemetry message!")
+                        parameters = self._parse_payload(payload)
+                        return await self._process_telemetry(cmd, parameters)
+
                     # Unknown messages
                     case _:
                         _LOGGER.debug(f"Received unknown message of type: {cmd.hex()}")
@@ -668,6 +677,18 @@ async def _process_negotiation(self, cmd: bytes, payload: bytes) -> None:
                 parameters = self._parse_payload(payload)
                 _LOGGER.debug(f"Parameters: {self._parameters_to_str(parameters)}")
 
+                # C200 DC appears to use an alternate handshake and does not
+                # provide a stage-5 public key (a1). For this path we accept
+                # the session as negotiated without setting AES key/IV.
+                if "a1" not in parameters:
+                    _LOGGER.debug(
+                        "Device did not provide a stage-5 public key. Assuming unencrypted session."
+                    )
+                    self._unencrypted_session = True
+                    if self._negotiation_timestamp is None:
+                        self._negotiation_timestamp = time.time()
+                    return
+
                 # Extract public key of device from payload
                 device_public_key_bytes = bytes.fromhex("04") + parameters["a1"]
                 _LOGGER.debug(f"Public key of device: {device_public_key_bytes.hex()}")
@@ -974,6 +995,7 @@ def _reset_session(self, reset_data: bool = True):
         self._telemetry_payload_large = None
         self._shared_key = None
         self._iv = None
+        self._unencrypted_session = False
         self._last_packet_timestamp = None
         self._negotiation_timestamp = None
         self._packet_futures: dict[bytes, list[asyncio.Future]] = {}
diff --git a/SolixBLE/devices/__init__.py b/SolixBLE/devices/__init__.py
index b68dd3a..eb27007 100644
--- a/SolixBLE/devices/__init__.py
+++ b/SolixBLE/devices/__init__.py
@@ -5,6 +5,7 @@
 """
 
 from .c300 import C300
+from .c200dc import C200DC
 from .c300dc import C300DC
 from .c800 import C800
 from .c1000 import C1000
@@ -18,6 +19,7 @@
 
 __all__ = [
     "C300",
+    "C200DC",
     "C300DC",
     "C800",
     "C1000",
diff --git a/SolixBLE/devices/c200dc.py b/SolixBLE/devices/c200dc.py
new file mode 100644
index 0000000..c931f75
--- /dev/null
+++ b/SolixBLE/devices/c200dc.py
@@ -0,0 +1,29 @@
+"""C200 DC power station model.
+
+.. moduleauthor:: Harvey Lelliott (flip-dots) <harveylelliott@duck.com>
+
+"""
+
+from ..const import DEFAULT_METADATA_BOOL
+from .c300dc import C300DC
+
+
+class C200DC(C300DC):
+    """
+    C200 DC Power Station.
+
+    The C200 DC telemetry layout is largely compatible with C300DC telemetry.
+    Some firmware variants do not expose all optional fields (e.g. f7).
+    """
+
+    _EXPECTED_TELEMETRY_LENGTH: int = 242
+
+    @property
+    def dc_12v_auto_on(self) -> bool:
+        """Configured DC Port Auto On.
+
+        :returns: Status of the DC auto on mode or default bool value if unsupported.
+        """
+        if self._data is None or "f7" not in self._data:
+            return DEFAULT_METADATA_BOOL
+        return bool(self._parse_int("f7", begin=1))