diff --git a/custom_components/bluetti_bt/const.py b/custom_components/bluetti_bt/const.py
index bf2c516..e2af5f7 100644
--- a/custom_components/bluetti_bt/const.py
+++ b/custom_components/bluetti_bt/const.py
@@ -176,4 +176,16 @@ ADDITIONAL_DEVICE_FIELDS = {
             "force_update": True,
         },
     ),
+    "ac_output_frequency": MqttFieldConfig(
+        type=MqttFieldType.NUMERIC,
+        setter=False,
+        advanced=False,
+        home_assistant_extra={
+            "name": "AC Output Frequency",
+            "unit_of_measurement": "Hz",
+            "device_class": "frequency",
+            "state_class": "measurement",
+            "force_update": True,
+        },
+    ),
 }
diff --git a/custom_components/bluetti_bt/coordinator.py b/custom_components/bluetti_bt/coordinator.py
index d6ef672..dffdd61 100644
--- a/custom_components/bluetti_bt/coordinator.py
+++ b/custom_components/bluetti_bt/coordinator.py
@@ -45,9 +45,11 @@ class DummyDevice(BluettiDevice):
             self.struct.add_decimal_field("adl400_ac_input_voltage_phase1", 1229, 1)
             self.struct.add_decimal_field("adl400_ac_input_voltage_phase2", 1237, 1)
             self.struct.add_decimal_field("adl400_ac_input_voltage_phase3", 1245, 1)
+            self.struct.add_decimal_field("ac_input_frequency", 1300, 1)
             self.struct.add_decimal_field("ac_input_voltage_phase1", 1314, 1)
             self.struct.add_decimal_field("ac_input_voltage_phase2", 1320, 1)
             self.struct.add_decimal_field("ac_input_voltage_phase3", 1326, 1)
+            self.struct.add_decimal_field("ac_output_frequency", 1500, 1)
             self.struct.add_decimal_field("ac_output_voltage_phase1", 1511, 1)
             self.struct.add_decimal_field("ac_output_voltage_phase2", 1518, 1)
             self.struct.add_decimal_field("ac_output_voltage_phase3", 1525, 1)
@@ -61,7 +63,9 @@ class DummyDevice(BluettiDevice):
             return [
                 ReadHoldingRegisters(100, 62),
                 ReadHoldingRegisters(1229, 19),
+                ReadHoldingRegisters(1300, 1),
                 ReadHoldingRegisters(1314, 13),
+                ReadHoldingRegisters(1500, 1),
                 ReadHoldingRegisters(1511, 15),
                 ReadHoldingRegisters(2022, 6),
                 ReadHoldingRegisters(2213, 4),