diff --git a/media/java/android/mtp/MtpDatabase.java b/media/java/android/mtp/MtpDatabase.java
index cc464db..2ddbb7d 100755
--- a/media/java/android/mtp/MtpDatabase.java
+++ b/media/java/android/mtp/MtpDatabase.java
@@ -16,15 +16,19 @@
 
 package android.mtp;
 
+import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.ContentValues;
 import android.content.IContentProvider;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.content.SharedPreferences;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.media.MediaScanner;
 import android.net.Uri;
+import android.os.BatteryManager;
+import android.os.BatteryStats;
 import android.os.RemoteException;
 import android.provider.MediaStore;
 import android.provider.MediaStore.Audio;
@@ -113,11 +117,35 @@
                                             + Files.FileColumns.PARENT + "=?";
 
     private final MediaScanner mMediaScanner;
+    private MtpServer mServer;
+
+    // read from native code
+    private int mBatteryLevel;
+    private int mBatteryScale;
 
     static {
         System.loadLibrary("media_jni");
     }
 
+    private BroadcastReceiver mBatteryReceiver = new BroadcastReceiver() {
+          @Override
+        public void onReceive(Context context, Intent intent) {
+            String action = intent.getAction();
+            if (action.equals(Intent.ACTION_BATTERY_CHANGED)) {
+                mBatteryScale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, 0);
+                int newLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
+                if (newLevel != mBatteryLevel) {
+                    mBatteryLevel = newLevel;
+                    if (mServer != null) {
+                        // send device property changed event
+                        mServer.sendDevicePropertyChanged(
+                                MtpConstants.DEVICE_PROPERTY_BATTERY_LEVEL);
+                    }
+                }
+            }
+        }
+    };
+
     public MtpDatabase(Context context, String volumeName, String storagePath,
             String[] subDirectories) {
         native_setup();
@@ -171,6 +199,18 @@
         initDeviceProperties(context);
     }
 
+    public void setServer(MtpServer server) {
+        mServer = server;
+
+        // register for battery notifications when we are connected
+        if (server != null) {
+            mContext.registerReceiver(mBatteryReceiver,
+                    new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+        } else {
+            mContext.unregisterReceiver(mBatteryReceiver);
+        }
+    }
+
     @Override
     protected void finalize() throws Throwable {
         try {
@@ -663,6 +703,7 @@
             MtpConstants.DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER,
             MtpConstants.DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME,
             MtpConstants.DEVICE_PROPERTY_IMAGE_SIZE,
+            MtpConstants.DEVICE_PROPERTY_BATTERY_LEVEL,
         };
     }
 
@@ -819,6 +860,8 @@
                 outStringValue[imageSize.length()] = 0;
                 return MtpConstants.RESPONSE_OK;
 
+            // DEVICE_PROPERTY_BATTERY_LEVEL is implemented in the JNI code
+
             default:
                 return MtpConstants.RESPONSE_DEVICE_PROP_NOT_SUPPORTED;
         }
diff --git a/media/java/android/mtp/MtpServer.java b/media/java/android/mtp/MtpServer.java
index 266f78e..3814630 100644
--- a/media/java/android/mtp/MtpServer.java
+++ b/media/java/android/mtp/MtpServer.java
@@ -30,6 +30,7 @@
 
     public MtpServer(MtpDatabase database, boolean usePtp) {
         native_setup(database, usePtp);
+        database.setServer(this);
     }
 
     public void start() {
@@ -51,6 +52,10 @@
         native_send_object_removed(handle);
     }
 
+    public void sendDevicePropertyChanged(int property) {
+        native_send_device_property_changed(property);
+    }
+
     public void addStorage(MtpStorage storage) {
         native_add_storage(storage);
     }
@@ -64,6 +69,7 @@
     private native final void native_cleanup();
     private native final void native_send_object_added(int handle);
     private native final void native_send_object_removed(int handle);
+    private native final void native_send_device_property_changed(int property);
     private native final void native_add_storage(MtpStorage storage);
     private native final void native_remove_storage(int storageId);
 }
diff --git a/media/jni/android_mtp_MtpDatabase.cpp b/media/jni/android_mtp_MtpDatabase.cpp
index 6b0bd0d..ea75a18 100644
--- a/media/jni/android_mtp_MtpDatabase.cpp
+++ b/media/jni/android_mtp_MtpDatabase.cpp
@@ -68,6 +68,8 @@
 static jmethodID method_sessionEnded;
 
 static jfieldID field_context;
+static jfieldID field_batteryLevel;
+static jfieldID field_batteryScale;
 
 // MtpPropertyList fields
 static jfieldID field_mCount;
@@ -527,68 +529,75 @@
 
 MtpResponseCode MyMtpDatabase::getDevicePropertyValue(MtpDeviceProperty property,
                                             MtpDataPacket& packet) {
-    int         type;
-
-    if (!getDevicePropertyInfo(property, type))
-        return MTP_RESPONSE_DEVICE_PROP_NOT_SUPPORTED;
-
     JNIEnv* env = AndroidRuntime::getJNIEnv();
-    jint result = env->CallIntMethod(mDatabase, method_getDeviceProperty,
-                (jint)property, mLongBuffer, mStringBuffer);
-    if (result != MTP_RESPONSE_OK) {
+
+    if (property == MTP_DEVICE_PROPERTY_BATTERY_LEVEL) {
+        // special case - implemented here instead of Java
+        packet.putUInt8((uint8_t)env->GetIntField(mDatabase, field_batteryLevel));
+        return MTP_RESPONSE_OK;
+    } else {
+        int type;
+
+        if (!getDevicePropertyInfo(property, type))
+            return MTP_RESPONSE_DEVICE_PROP_NOT_SUPPORTED;
+
+        jint result = env->CallIntMethod(mDatabase, method_getDeviceProperty,
+                    (jint)property, mLongBuffer, mStringBuffer);
+        if (result != MTP_RESPONSE_OK) {
+            checkAndClearExceptionFromCallback(env, __FUNCTION__);
+            return result;
+        }
+
+        jlong* longValues = env->GetLongArrayElements(mLongBuffer, 0);
+        jlong longValue = longValues[0];
+        env->ReleaseLongArrayElements(mLongBuffer, longValues, 0);
+
+        switch (type) {
+            case MTP_TYPE_INT8:
+                packet.putInt8(longValue);
+                break;
+            case MTP_TYPE_UINT8:
+                packet.putUInt8(longValue);
+                break;
+            case MTP_TYPE_INT16:
+                packet.putInt16(longValue);
+                break;
+            case MTP_TYPE_UINT16:
+                packet.putUInt16(longValue);
+                break;
+            case MTP_TYPE_INT32:
+                packet.putInt32(longValue);
+                break;
+            case MTP_TYPE_UINT32:
+                packet.putUInt32(longValue);
+                break;
+            case MTP_TYPE_INT64:
+                packet.putInt64(longValue);
+                break;
+            case MTP_TYPE_UINT64:
+                packet.putUInt64(longValue);
+                break;
+            case MTP_TYPE_INT128:
+                packet.putInt128(longValue);
+                break;
+            case MTP_TYPE_UINT128:
+                packet.putInt128(longValue);
+                break;
+            case MTP_TYPE_STR:
+            {
+                jchar* str = env->GetCharArrayElements(mStringBuffer, 0);
+                packet.putString(str);
+                env->ReleaseCharArrayElements(mStringBuffer, str, 0);
+                break;
+             }
+            default:
+                ALOGE("unsupported type in getDevicePropertyValue\n");
+                return MTP_RESPONSE_INVALID_DEVICE_PROP_FORMAT;
+        }
+
         checkAndClearExceptionFromCallback(env, __FUNCTION__);
-        return result;
+        return MTP_RESPONSE_OK;
     }
-
-    jlong* longValues = env->GetLongArrayElements(mLongBuffer, 0);
-    jlong longValue = longValues[0];
-    env->ReleaseLongArrayElements(mLongBuffer, longValues, 0);
-
-    switch (type) {
-        case MTP_TYPE_INT8:
-            packet.putInt8(longValue);
-            break;
-        case MTP_TYPE_UINT8:
-            packet.putUInt8(longValue);
-            break;
-        case MTP_TYPE_INT16:
-            packet.putInt16(longValue);
-            break;
-        case MTP_TYPE_UINT16:
-            packet.putUInt16(longValue);
-            break;
-        case MTP_TYPE_INT32:
-            packet.putInt32(longValue);
-            break;
-        case MTP_TYPE_UINT32:
-            packet.putUInt32(longValue);
-            break;
-        case MTP_TYPE_INT64:
-            packet.putInt64(longValue);
-            break;
-        case MTP_TYPE_UINT64:
-            packet.putUInt64(longValue);
-            break;
-        case MTP_TYPE_INT128:
-            packet.putInt128(longValue);
-            break;
-        case MTP_TYPE_UINT128:
-            packet.putInt128(longValue);
-            break;
-        case MTP_TYPE_STR:
-        {
-            jchar* str = env->GetCharArrayElements(mStringBuffer, 0);
-            packet.putString(str);
-            env->ReleaseCharArrayElements(mStringBuffer, str, 0);
-            break;
-         }
-        default:
-            ALOGE("unsupported type in getDevicePropertyValue\n");
-            return MTP_RESPONSE_INVALID_DEVICE_PROP_FORMAT;
-    }
-
-    checkAndClearExceptionFromCallback(env, __FUNCTION__);
-    return MTP_RESPONSE_OK;
 }
 
 MtpResponseCode MyMtpDatabase::setDevicePropertyValue(MtpDeviceProperty property,
@@ -923,6 +932,7 @@
     {   MTP_DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER,    MTP_TYPE_STR },
     {   MTP_DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME,       MTP_TYPE_STR },
     {   MTP_DEVICE_PROPERTY_IMAGE_SIZE,                 MTP_TYPE_STR },
+    {   MTP_DEVICE_PROPERTY_BATTERY_LEVEL,              MTP_TYPE_UINT8 },
 };
 
 bool MyMtpDatabase::getObjectPropertyInfo(MtpObjectProperty property, int& type) {
@@ -1046,7 +1056,7 @@
         case MTP_DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME:
             writable = true;
             // fall through
-        case MTP_DEVICE_PROPERTY_IMAGE_SIZE:
+        case MTP_DEVICE_PROPERTY_IMAGE_SIZE: {
             result = new MtpProperty(property, MTP_TYPE_STR, writable);
 
             // get current value
@@ -1063,6 +1073,12 @@
                 ALOGE("unable to read device property, response: %04X", ret);
             }
             break;
+        }
+        case MTP_DEVICE_PROPERTY_BATTERY_LEVEL:
+            result = new MtpProperty(property, MTP_TYPE_UINT8);
+            result->setFormRange(0, env->GetIntField(mDatabase, field_batteryScale), 1);
+            result->mCurrentValue.u.u8 = (uint8_t)env->GetIntField(mDatabase, field_batteryLevel);
+            break;
     }
 
     checkAndClearExceptionFromCallback(env, __FUNCTION__);
@@ -1234,6 +1250,16 @@
         ALOGE("Can't find MtpDatabase.mNativeContext");
         return -1;
     }
+    field_batteryLevel = env->GetFieldID(clazz, "mBatteryLevel", "I");
+    if (field_batteryLevel == NULL) {
+        ALOGE("Can't find MtpDatabase.mBatteryLevel");
+        return -1;
+    }
+    field_batteryScale = env->GetFieldID(clazz, "mBatteryScale", "I");
+    if (field_batteryScale == NULL) {
+        ALOGE("Can't find MtpDatabase.mBatteryScale");
+        return -1;
+    }
 
     // now set up fields for MtpPropertyList class
     clazz = env->FindClass("android/mtp/MtpPropertyList");
diff --git a/media/jni/android_mtp_MtpServer.cpp b/media/jni/android_mtp_MtpServer.cpp
index 9d7f1c2..2f90dfe 100644
--- a/media/jni/android_mtp_MtpServer.cpp
+++ b/media/jni/android_mtp_MtpServer.cpp
@@ -118,6 +118,18 @@
 }
 
 static void
+android_mtp_MtpServer_send_device_property_changed(JNIEnv *env, jobject thiz, jint property)
+{
+    Mutex::Autolock autoLock(sMutex);
+
+    MtpServer* server = getMtpServer(env, thiz);
+    if (server)
+        server->sendDevicePropertyChanged(property);
+    else
+        ALOGE("server is null in send_object_removed");
+}
+
+static void
 android_mtp_MtpServer_add_storage(JNIEnv *env, jobject thiz, jobject jstorage)
 {
     Mutex::Autolock autoLock(sMutex);
@@ -174,6 +186,8 @@
     {"native_cleanup",              "()V",  (void *)android_mtp_MtpServer_cleanup},
     {"native_send_object_added",    "(I)V", (void *)android_mtp_MtpServer_send_object_added},
     {"native_send_object_removed",  "(I)V", (void *)android_mtp_MtpServer_send_object_removed},
+    {"native_send_device_property_changed",  "(I)V",
+                                    (void *)android_mtp_MtpServer_send_device_property_changed},
     {"native_add_storage",          "(Landroid/mtp/MtpStorage;)V",
                                             (void *)android_mtp_MtpServer_add_storage},
     {"native_remove_storage",       "(I)V", (void *)android_mtp_MtpServer_remove_storage},