diff --git a/services/sensorservice/Android.mk b/services/sensorservice/Android.mk
index 6a302c0..e0cfaa6 100644
--- a/services/sensorservice/Android.mk
+++ b/services/sensorservice/Android.mk
@@ -2,6 +2,7 @@
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= \
+	BatteryService.cpp \
 	CorrectedGyroSensor.cpp \
     Fusion.cpp \
     GravitySensor.cpp \
diff --git a/services/sensorservice/BatteryService.cpp b/services/sensorservice/BatteryService.cpp
new file mode 100644
index 0000000..70b65ab
--- /dev/null
+++ b/services/sensorservice/BatteryService.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <math.h>
+#include <sys/types.h>
+
+#include <utils/Atomic.h>
+#include <utils/Errors.h>
+#include <utils/Singleton.h>
+
+#include <binder/BinderService.h>
+#include <binder/Parcel.h>
+
+#include "BatteryService.h"
+
+namespace android {
+// ---------------------------------------------------------------------------
+
+BatteryService::BatteryService() {
+    const sp<IServiceManager> sm(defaultServiceManager());
+    if (sm != NULL) {
+        const String16 name("batteryinfo");
+        mBatteryStatService = sm->getService(name);
+    }
+}
+
+status_t BatteryService::noteStartSensor(int uid, int handle) {
+    Parcel data, reply;
+    data.writeInterfaceToken(DESCRIPTOR);
+    data.writeInt32(uid);
+    data.writeInt32(handle);
+    status_t err = mBatteryStatService->transact(
+            TRANSACTION_noteStartSensor, data, &reply, 0);
+    err = reply.readExceptionCode();
+    return err;
+}
+
+status_t BatteryService::noteStopSensor(int uid, int handle) {
+    Parcel data, reply;
+    data.writeInterfaceToken(DESCRIPTOR);
+    data.writeInt32(uid);
+    data.writeInt32(handle);
+    status_t err = mBatteryStatService->transact(
+            TRANSACTION_noteStopSensor, data, &reply, 0);
+    err = reply.readExceptionCode();
+    return err;
+}
+
+bool BatteryService::addSensor(uid_t uid, int handle) {
+    Mutex::Autolock _l(mActivationsLock);
+    Info key(uid, handle);
+    ssize_t index = mActivations.indexOf(key);
+    if (index < 0) {
+        index = mActivations.add(key);
+    }
+    Info& info(mActivations.editItemAt(index));
+    info.count++;
+    return info.count == 1;
+}
+
+bool BatteryService::removeSensor(uid_t uid, int handle) {
+    Mutex::Autolock _l(mActivationsLock);
+    ssize_t index = mActivations.indexOf(Info(uid, handle));
+    if (index < 0) return false;
+    Info& info(mActivations.editItemAt(index));
+    info.count--;
+    return info.count == 0;
+}
+
+
+void BatteryService::enableSensorImpl(uid_t uid, int handle) {
+    if (mBatteryStatService != 0) {
+        if (addSensor(uid, handle)) {
+            int64_t identity = IPCThreadState::self()->clearCallingIdentity();
+            noteStartSensor(uid, handle);
+            IPCThreadState::self()->restoreCallingIdentity(identity);
+        }
+    }
+}
+void BatteryService::disableSensorImpl(uid_t uid, int handle) {
+    if (mBatteryStatService != 0) {
+        if (removeSensor(uid, handle)) {
+            int64_t identity = IPCThreadState::self()->clearCallingIdentity();
+            noteStopSensor(uid, handle);
+            IPCThreadState::self()->restoreCallingIdentity(identity);
+        }
+    }
+}
+
+void BatteryService::cleanupImpl(uid_t uid) {
+    if (mBatteryStatService != 0) {
+        Mutex::Autolock _l(mActivationsLock);
+        int64_t identity = IPCThreadState::self()->clearCallingIdentity();
+        for (ssize_t i=0 ; i<mActivations.size() ; i++) {
+            const Info& info(mActivations[i]);
+            if (info.uid == uid) {
+                noteStopSensor(info.uid, info.handle);
+                mActivations.removeAt(i);
+                i--;
+            }
+        }
+        IPCThreadState::self()->restoreCallingIdentity(identity);
+    }
+}
+
+const String16 BatteryService::DESCRIPTOR("com.android.internal.app.IBatteryStats");
+
+ANDROID_SINGLETON_STATIC_INSTANCE(BatteryService)
+
+// ---------------------------------------------------------------------------
+}; // namespace android
+
diff --git a/services/sensorservice/BatteryService.h b/services/sensorservice/BatteryService.h
new file mode 100644
index 0000000..86cc884
--- /dev/null
+++ b/services/sensorservice/BatteryService.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <utils/Singleton.h>
+
+namespace android {
+// ---------------------------------------------------------------------------
+
+class BatteryService : public Singleton<BatteryService> {
+    static const int TRANSACTION_noteStartSensor = IBinder::FIRST_CALL_TRANSACTION + 3;
+    static const int TRANSACTION_noteStopSensor = IBinder::FIRST_CALL_TRANSACTION + 4;
+    static const String16 DESCRIPTOR;
+
+    friend class Singleton<BatteryService>;
+    sp<IBinder> mBatteryStatService;
+
+    BatteryService();
+    status_t noteStartSensor(int uid, int handle);
+    status_t noteStopSensor(int uid, int handle);
+
+    void enableSensorImpl(uid_t uid, int handle);
+    void disableSensorImpl(uid_t uid, int handle);
+    void cleanupImpl(uid_t uid);
+
+    struct Info {
+        uid_t uid;
+        int handle;
+        int32_t count;
+        Info()  : uid(0), handle(0), count(0) { }
+        Info(uid_t uid, int handle) : uid(uid), handle(handle), count(0) { }
+        bool operator < (const Info& rhs) const {
+            return (uid == rhs.uid) ? (handle < rhs.handle) :  (uid < rhs.uid);
+        }
+    };
+
+    Mutex mActivationsLock;
+    SortedVector<Info> mActivations;
+    bool addSensor(uid_t uid, int handle);
+    bool removeSensor(uid_t uid, int handle);
+
+public:
+    static void enableSensor(uid_t uid, int handle) {
+        BatteryService::getInstance().enableSensorImpl(uid, handle);
+    }
+    static void disableSensor(uid_t uid, int handle) {
+        BatteryService::getInstance().disableSensorImpl(uid, handle);
+    }
+    static void cleanup(uid_t uid) {
+        BatteryService::getInstance().cleanupImpl(uid);
+    }
+};
+
+// ---------------------------------------------------------------------------
+}; // namespace android
+
diff --git a/services/sensorservice/SensorDevice.cpp b/services/sensorservice/SensorDevice.cpp
index 2244a86..a9e3ef4 100644
--- a/services/sensorservice/SensorDevice.cpp
+++ b/services/sensorservice/SensorDevice.cpp
@@ -33,68 +33,6 @@
 
 namespace android {
 // ---------------------------------------------------------------------------
-class BatteryService : public Singleton<BatteryService> {
-    static const int TRANSACTION_noteStartSensor = IBinder::FIRST_CALL_TRANSACTION + 3;
-    static const int TRANSACTION_noteStopSensor = IBinder::FIRST_CALL_TRANSACTION + 4;
-    static const String16 DESCRIPTOR;
-
-    friend class Singleton<BatteryService>;
-    sp<IBinder> mBatteryStatService;
-
-    BatteryService() {
-        const sp<IServiceManager> sm(defaultServiceManager());
-        if (sm != NULL) {
-            const String16 name("batteryinfo");
-            mBatteryStatService = sm->getService(name);
-        }
-    }
-
-    status_t noteStartSensor(int uid, int handle) {
-        Parcel data, reply;
-        data.writeInterfaceToken(DESCRIPTOR);
-        data.writeInt32(uid);
-        data.writeInt32(handle);
-        status_t err = mBatteryStatService->transact(
-                TRANSACTION_noteStartSensor, data, &reply, 0);
-        err = reply.readExceptionCode();
-        return err;
-    }
-
-    status_t noteStopSensor(int uid, int handle) {
-        Parcel data, reply;
-        data.writeInterfaceToken(DESCRIPTOR);
-        data.writeInt32(uid);
-        data.writeInt32(handle);
-        status_t err = mBatteryStatService->transact(
-                TRANSACTION_noteStopSensor, data, &reply, 0);
-        err = reply.readExceptionCode();
-        return err;
-    }
-
-public:
-    void enableSensor(int handle) {
-        if (mBatteryStatService != 0) {
-            int uid = IPCThreadState::self()->getCallingUid();
-            int64_t identity = IPCThreadState::self()->clearCallingIdentity();
-            noteStartSensor(uid, handle);
-            IPCThreadState::self()->restoreCallingIdentity(identity);
-        }
-    }
-    void disableSensor(int handle) {
-        if (mBatteryStatService != 0) {
-            int uid = IPCThreadState::self()->getCallingUid();
-            int64_t identity = IPCThreadState::self()->clearCallingIdentity();
-            noteStopSensor(uid, handle);
-            IPCThreadState::self()->restoreCallingIdentity(identity);
-        }
-    }
-};
-
-const String16 BatteryService::DESCRIPTOR("com.android.internal.app.IBatteryStats");
-
-ANDROID_SINGLETON_STATIC_INSTANCE(BatteryService)
-
-// ---------------------------------------------------------------------------
 
 ANDROID_SINGLETON_STATIC_INSTANCE(SensorDevice)
 
@@ -218,16 +156,9 @@
         ALOGD_IF(DEBUG_CONNECTIONS, "\t>>> actuating h/w");
 
         err = mSensorDevice->activate(mSensorDevice, handle, enabled);
-        if (enabled) {
-            ALOGE_IF(err, "Error activating sensor %d (%s)", handle, strerror(-err));
-            if (err == 0) {
-                BatteryService::getInstance().enableSensor(handle);
-            }
-        } else {
-            if (err == 0) {
-                BatteryService::getInstance().disableSensor(handle);
-            }
-        }
+        ALOGE_IF(err, "Error %s sensor %d (%s)",
+                enabled ? "activating" : "disabling",
+                handle, strerror(-err));
     }
 
     { // scope for the lock
diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index cc2f745..e3dcd02 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -39,6 +39,7 @@
 
 #include <hardware/sensors.h>
 
+#include "BatteryService.h"
 #include "CorrectedGyroSensor.h"
 #include "GravitySensor.h"
 #include "LinearAccelerationSensor.h"
@@ -421,6 +422,7 @@
         }
     }
     mActiveConnections.remove(connection);
+    BatteryService::cleanup(c->getUid());
 }
 
 status_t SensorService::enable(const sp<SensorEventConnection>& connection,
@@ -458,6 +460,7 @@
         if (err == NO_ERROR) {
             // connection now active
             if (connection->addSensor(handle)) {
+                BatteryService::enableSensor(connection->getUid(), handle);
                 // the sensor was added (which means it wasn't already there)
                 // so, see if this connection becomes active
                 if (mActiveConnections.indexOf(connection) < 0) {
@@ -483,7 +486,9 @@
     SensorRecord* rec = mActiveSensors.valueFor(handle);
     if (rec) {
         // see if this connection becomes inactive
-        connection->removeSensor(handle);
+        if (connection->removeSensor(handle)) {
+            BatteryService::disableSensor(connection->getUid(), handle);
+        }
         if (connection->hasAnySensor() == false) {
             mActiveConnections.remove(connection);
         }