Merge pull request #1017 from sstoops/master

Add `Renogy.unique_identifier` method to allow multiple batteries

etc/dbus-serialbattery/bms/renogy.py

@@ -41,6 +41,10 @@ def __init__(self, port, baud, address):
     )
     # BMS warning and protection config
 
+
+    def unique_identifier(self) -> str:
+        return self.serial_number
+
     def test_connection(self):
         # call a function that will connect to the battery, send a command and retrieve the result.
         # The result or call should be unique to this BMS. Battery name or version, etc.
@@ -125,6 +129,9 @@ def read_gen_data(self):
         capacity = self.read_serial_data_renogy(self.command_capacity)
         self.capacity = unpack(">L", capacity)[0] / 1000.0
 
+        serial_number = self.read_serial_data_renogy(self.command_serial_number)
+        self.serial_number = unpack("16s", serial_number)[0].decode("utf-8")
+
         return True
 
     def read_soc_data(self):