title: How to get the battery level after connect to the BLE device?
body: <p>I am developing an application where I have to connect to Bluetooth device on Android 4.3.</p>
  
  <p>And I want to get the battery level by using <strong>Battery_Service</strong> and <strong>Battery_Level</strong>.</p>
  
  <pre><code>public class BluetoothLeService extends Service {
  
      private static final UUID Battery_Service_UUID =
                  UUID.fromString("0000180F-0000-1000-8000-00805f9b34fb");
  
      private static final UUID Battery_Level_UUID =
                  UUID.fromString("00002a19-0000-1000-8000-00805f9b34fb");
  
  
      public void getbattery() {
  
          BluetoothGattService batteryService = mBluetoothGatt.getService(Battery_Service_UUID);
          if(batteryService == null) {
              Log.d(TAG, "Battery service not found!");
              return;
          }
  
          BluetoothGattCharacteristic batteryLevel = batteryService.getCharacteristic(Battery_Level_UUID);
          if(batteryLevel == null) {
              Log.d(TAG, "Battery level not found!");
              return;
          }
  
           mBluetoothGatt.readCharacteristic(batteryLevel);
      　　　　　// What should I do that I can get the battery level ??
           Log.d(TAG, "Battery level " + mBluetoothGatt.readCharacteristic(batteryLevel););
      }
  
  }
  </code></pre>
  
  <p>But the value of <code>mBluetoothGatt.readCharacteristic(batteryLevel);</code> is not the battery level value</p>
  
  <p>How to read the battery?</p>