How to get current battery life on mobile device

Sorry to revive an old thread, (this is the first google result) but here's an android solution[1] that doesn't require a plugin; I couldn't work out how to get the above to work, and using JNI was a bit of a pain.

 int GetBatteryLevel()
     {
         try {
             string CapacityString = System.IO.File.ReadAllText ("/sys/class/power_supply/battery/capacity");
             return int.Parse (CapacityString);
         } catch (Exception e) {
             Debug.Log ("Failed to read battery power; " + e.Message);
         }
 
         return -1;
     }

[1] Only tested on my Note4, and I believe the file location could change, and you can have multiple batteries etc

   public static float GetBatteryLevel()
     {
         #if UNITY_IOS
         UIDevice device = UIDevice.CurrentDevice();
         device.batteryMonitoringEnabled = true; // need to enable this first
         Debug.Log("Battery state: " + device.batteryState);
         Debug.Log("Battery level: " + device.batteryLevel);
         return device.batteryLevel*100;
         #elif UNITY_ANDROID
 
         if (Application.platform == RuntimePlatform.Android)
         {
             try
             {
                 using (AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
                 {
                     if (null != unityPlayer)
                     {
                         using (AndroidJavaObject currActivity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
                         {
                             if (null != currActivity)
                             {
                                 using (AndroidJavaObject intentFilter = new AndroidJavaObject("android.content.IntentFilter", new object[]{ "android.intent.action.BATTERY_CHANGED" }))
                                 {
                                     using (AndroidJavaObject batteryIntent = currActivity.Call<AndroidJavaObject>("registerReceiver", new object[]{null,intentFilter}))
                                     {
                                         int level = batteryIntent.Call<int>("getIntExtra", new object[]{"level",-1});
                                         int scale = batteryIntent.Call<int>("getIntExtra", new object[]{"scale",-1});
 
                                         // Error checking that probably isn't needed but I added just in case.
                                         if (level == -1 || scale == -1)
                                         {
                                             return 50f;
                                         }
                                         return ((float)level / (float)scale) * 100.0f; 
                                     }
                                 
                                 }
                             }
                         }
                     }
                 }
             } catch (System.Exception ex)
             {
               
             }
         }
        
         return 100;
         #endif
     }