diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index 22030558035..a71dc99abdd 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -749,8 +749,22 @@ NS_IMETHODIMP
 Navigator::GetMozBattery(nsIDOMBatteryManager** aBattery)
 {
   if (!mBatteryManager) {
+    *aBattery = nsnull;
+
+    nsCOMPtr<nsPIDOMWindow> window = do_GetInterface(mDocShell);
+    NS_ENSURE_TRUE(window, NS_OK);
+
+    nsCOMPtr<nsIDocument> document = do_GetInterface(mDocShell);
+    NS_ENSURE_TRUE(document, NS_OK);
+
+    nsIScriptGlobalObject* sgo = document->GetScopeObject();
+    NS_ENSURE_TRUE(sgo, NS_OK);
+
+    nsIScriptContext* scx = sgo->GetContext();
+    NS_ENSURE_TRUE(scx, NS_OK);
+
     mBatteryManager = new battery::BatteryManager();
-    mBatteryManager->Init();
+    mBatteryManager->Init(window->GetCurrentInnerWindow(), scx);
   }
 
   NS_ADDREF(*aBattery = mBatteryManager);
diff --git a/dom/battery/BatteryManager.cpp b/dom/battery/BatteryManager.cpp
index b5fdfee9f07..2e7fb298c61 100644
--- a/dom/battery/BatteryManager.cpp
+++ b/dom/battery/BatteryManager.cpp
@@ -61,26 +61,28 @@ namespace battery {
 NS_IMPL_CYCLE_COLLECTION_CLASS(BatteryManager)
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(BatteryManager,
-                                                  nsDOMEventTargetHelper)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mOnLevelChangeListener)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mOnChargingChangeListener)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mOnDischargingTimeChangeListener)
+                                                  nsDOMEventTargetWrapperCache)
+  NS_CYCLE_COLLECTION_TRAVERSE_EVENT_HANDLER(levelchange)
+  NS_CYCLE_COLLECTION_TRAVERSE_EVENT_HANDLER(chargingchange)
+  NS_CYCLE_COLLECTION_TRAVERSE_EVENT_HANDLER(chargingtimechange)
+  NS_CYCLE_COLLECTION_TRAVERSE_EVENT_HANDLER(dischargingtimechange)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(BatteryManager,
-                                                nsDOMEventTargetHelper)
-  NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mOnLevelChangeListener)
-  NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mOnChargingChangeListener)
-  NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mOnDischargingTimeChangeListener)
+                                                nsDOMEventTargetWrapperCache)
+  NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(levelchange)
+  NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(chargingchange)
+  NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(chargingtimechange)
+  NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(dischargingtimechange)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(BatteryManager)
   NS_INTERFACE_MAP_ENTRY(nsIDOMBatteryManager)
   NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(BatteryManager)
-NS_INTERFACE_MAP_END_INHERITING(nsDOMEventTargetHelper)
+NS_INTERFACE_MAP_END_INHERITING(nsDOMEventTargetWrapperCache)
 
-NS_IMPL_ADDREF_INHERITED(BatteryManager, nsDOMEventTargetHelper)
-NS_IMPL_RELEASE_INHERITED(BatteryManager, nsDOMEventTargetHelper)
+NS_IMPL_ADDREF_INHERITED(BatteryManager, nsDOMEventTargetWrapperCache)
+NS_IMPL_RELEASE_INHERITED(BatteryManager, nsDOMEventTargetWrapperCache)
 
 BatteryManager::BatteryManager()
   : mLevel(kDefaultLevel)
@@ -97,8 +99,12 @@ BatteryManager::~BatteryManager()
 }
 
 void
-BatteryManager::Init()
+BatteryManager::Init(nsPIDOMWindow *aWindow, nsIScriptContext* aScriptContext)
 {
+  // Those vars come from nsDOMEventTargetHelper.
+  mOwner = aWindow;
+  mScriptContext = aScriptContext;
+
   hal::RegisterBatteryObserver(this);
 
   hal::BatteryInformation* batteryInfo = new hal::BatteryInformation();
@@ -157,61 +163,10 @@ BatteryManager::GetChargingTime(double* aChargingTime)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-BatteryManager::GetOnlevelchange(nsIDOMEventListener** aOnlevelchange)
-{
-  return GetInnerEventListener(mOnLevelChangeListener, aOnlevelchange);
-}
-
-NS_IMETHODIMP
-BatteryManager::SetOnlevelchange(nsIDOMEventListener* aOnlevelchange)
-{
-  return RemoveAddEventListener(LEVELCHANGE_EVENT_NAME, mOnLevelChangeListener,
-                                aOnlevelchange);
-}
-
-NS_IMETHODIMP
-BatteryManager::GetOnchargingchange(nsIDOMEventListener** aOnchargingchange)
-{
-  return GetInnerEventListener(mOnChargingChangeListener, aOnchargingchange);
-}
-
-NS_IMETHODIMP
-BatteryManager::SetOnchargingchange(nsIDOMEventListener* aOnchargingchange)
-{
-  return RemoveAddEventListener(CHARGINGCHANGE_EVENT_NAME,
-                                mOnChargingChangeListener, aOnchargingchange);
-}
-
-NS_IMETHODIMP
-BatteryManager::GetOndischargingtimechange(nsIDOMEventListener** aOndischargingtimechange)
-{
-  return GetInnerEventListener(mOnDischargingTimeChangeListener,
-                               aOndischargingtimechange);
-}
-
-NS_IMETHODIMP
-BatteryManager::SetOndischargingtimechange(nsIDOMEventListener* aOndischargingtimechange)
-{
-  return RemoveAddEventListener(DISCHARGINGTIMECHANGE_EVENT_NAME,
-                                mOnDischargingTimeChangeListener,
-                                aOndischargingtimechange);
-}
-
-NS_IMETHODIMP
-BatteryManager::GetOnchargingtimechange(nsIDOMEventListener** aOnchargingtimechange)
-{
-  return GetInnerEventListener(mOnChargingTimeChangeListener,
-                               aOnchargingtimechange);
-}
-
-NS_IMETHODIMP
-BatteryManager::SetOnchargingtimechange(nsIDOMEventListener* aOnchargingtimechange)
-{
-  return RemoveAddEventListener(CHARGINGTIMECHANGE_EVENT_NAME,
-                                mOnChargingTimeChangeListener,
-                                aOnchargingtimechange);
-}
+NS_IMPL_EVENT_HANDLER(BatteryManager, levelchange)
+NS_IMPL_EVENT_HANDLER(BatteryManager, chargingchange)
+NS_IMPL_EVENT_HANDLER(BatteryManager, chargingtimechange)
+NS_IMPL_EVENT_HANDLER(BatteryManager, dischargingtimechange)
 
 nsresult
 BatteryManager::DispatchTrustedEventToSelf(const nsAString& aEventName)
diff --git a/dom/battery/BatteryManager.h b/dom/battery/BatteryManager.h
index e4a4072df2f..2b34ca22511 100644
--- a/dom/battery/BatteryManager.h
+++ b/dom/battery/BatteryManager.h
@@ -39,11 +39,14 @@
 #define mozilla_dom_battery_BatteryManager_h
 
 #include "nsIDOMBatteryManager.h"
-#include "nsDOMEventTargetHelper.h"
+#include "nsDOMEventTargetWrapperCache.h"
 #include "nsCycleCollectionParticipant.h"
 #include "mozilla/Observer.h"
 #include "Types.h"
 
+class nsPIDOMWindow;
+class nsIScriptContext;
+
 namespace mozilla {
 
 namespace hal {
@@ -53,26 +56,26 @@ class BatteryInformation;
 namespace dom {
 namespace battery {
 
-class BatteryManager : public nsIDOMBatteryManager
-                     , public nsDOMEventTargetHelper
+class BatteryManager : public nsDOMEventTargetWrapperCache
+                     , public nsIDOMBatteryManager
                      , public BatteryObserver
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIDOMBATTERYMANAGER
-  NS_FORWARD_NSIDOMEVENTTARGET(nsDOMEventTargetHelper::)
+  NS_FORWARD_NSIDOMEVENTTARGET(nsDOMEventTargetWrapperCache::)
 
   BatteryManager();
   virtual ~BatteryManager();
 
-  void Init();
+  void Init(nsPIDOMWindow *aWindow, nsIScriptContext* aScriptContext);
   void Shutdown();
 
   // For IObserver.
   void Notify(const hal::BatteryInformation& aBatteryInfo);
 
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(BatteryManager,
-                                           nsDOMEventTargetHelper)
+                                           nsDOMEventTargetWrapperCache)
 
   /**
    * Returns whether the battery api is supported (ie. not disabled by the user)
@@ -101,10 +104,10 @@ private:
    */
   double mRemainingTime;
 
-  nsRefPtr<nsDOMEventListenerWrapper> mOnLevelChangeListener;
-  nsRefPtr<nsDOMEventListenerWrapper> mOnChargingChangeListener;
-  nsRefPtr<nsDOMEventListenerWrapper> mOnDischargingTimeChangeListener;
-  nsRefPtr<nsDOMEventListenerWrapper> mOnChargingTimeChangeListener;
+  NS_DECL_EVENT_HANDLER(levelchange);
+  NS_DECL_EVENT_HANDLER(chargingchange);
+  NS_DECL_EVENT_HANDLER(chargingtimechange);
+  NS_DECL_EVENT_HANDLER(dischargingtimechange);
 };
 
 } // namespace battery