Add get_time_remaining()

proxy/server.py

@@ -250,6 +250,10 @@ def do_GET(self):
                     pod["PW%d_POD_nom_full_pack_energy" % idx] = get_value(d, 'POD_nom_full_pack_energy')
                     idx = idx + 1
             pod["backup_reserve_percent"] = pw.get_reserve()
+            d = pw.system_status()
+            pod["nominal_full_pack_energy"] = get_value(d,'nominal_full_pack_energy')
+            pod["nominal_energy_remaining"] = get_value(d,'nominal_energy_remaining')            
+            pod["time_remaining_hours"] = pw.get_time_remaining()
             message = json.dumps(pod) 
         elif self.path == '/version':
             # Firmware Version

pypowerwall/__init__.py

@@ -749,4 +749,27 @@ def battery_blocks(self, jsonformat=False):
         if jsonformat:
             return json.dumps(result, indent=4, sort_keys=True)
         else:
-            return result
+            return result
+
+    def get_time_remaining(self):
+        """
+        Get the backup time remaining on the battery
+
+        Returns:
+            The time remaining in hours
+        """
+        if self.cloudmode:                
+            d = self.Tesla.get_time_remaining()
+            # {'response': {'time_remaining_hours': 7.909122698326978}}
+            if d is None:
+                return None
+            if 'response' in d and 'time_remaining_hours' in d['response']:
+                return d['response']['time_remaining_hours']    
+
+        # Compute based on battery level and load
+        d = self.system_status()
+        if 'nominal_energy_remaining' in d:
+            return d['nominal_energy_remaining']/self.load()
+        # Default            
+        return None
+