Save current battery level when locking screen not working

I'm trying to save the current battery level when the user presses the power button (--> screen off).

At first I'm having a broadcast receiver which starts whenever the phone boots. It's task is to start a service, which creates another broadcast receiver for the screen-off/on intents (- since the screen off intent won't work when it is specified in the manifest, I'm creating it dynamically via this service)

MyStartupReceiver

public class MyStartupReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context c, Intent i) {
        if(i.getAction().equals(Intent.ACTION_BOOT_COMPLETED))
        {
            Log.d("Boot completed", "Boot completed");
            c.startService(new Intent(c, CreateReceiverService.class));
        }
    }
}

CreateReceiverService

public class CreateReceiverService extends Service {



    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO Auto-generated method stub

        IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_USER_PRESENT);
        filter.addAction(Intent.ACTION_BATTERY_CHANGED);

        BroadcastReceiver mReceiver = new ScreenReceiver();
        registerReceiver(mReceiver, filter);    
        Log.d("Service", "Receiver registered");
        return super.onStartCommand(intent, flags, startId);
    }

And here's the ScreenReceiver

public class ScreenReceiver extends BroadcastReceiver {

    private int lastBatteryLevel;

    @Override
    public void onReceive(Context c, Intent i) {
        if(i.getAction().equals(Intent.ACTION_USER_PRESENT))
        {
            Log.d("Screen unlock", "Screen unlock");
        }
        else if(i.getAction().equals(Intent.ACTION_SCREEN_OFF))
        {
            Log.d("Screen off", "Screen off");
            Intent s = new Intent(c, ActionService.class);
            s.putExtra("LVL", lastBatteryLevel);
            c.startService(s);
        }
        else if(i.getAction().equals(Intent.ACTION_BATTERY_CHANGED))
        {
            lastBatteryLevel = i.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
            Log.d("Battery changed", "level = "+lastBatteryLevel);
        }
    }

Now my problem: The ActionService should save the battery level to a preferences file: ActionService

public class ActionService extends Service {

    private SharedPreferences p = PreferenceManager.getDefaultSharedPreferences(this);
    Editor e = p.edit();

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO Auto-generated method stub

        e.putInt("LOCKLVL", intent.getIntExtra("LVL", -1));
        e.commit();
        Log.d("Saved preference", "saved "+p.getInt("LOCKLVL", -1));
        return super.onStartCommand(intent, flags, startId);
    }

The problem is that nothing happens when the screen off intent is received - my ActionService, which should save the battery level, is not called.

My Logcat output is:

Receiver registered
Screen off

and no output from ActionService's Log.d("Saved preference", "saved "+p.getInt("LOCKLVL", -1));

I even tried to set a wakelock like this: ScreenReceiver

else if(i.getAction().equals(Intent.ACTION_SCREEN_OFF))
        {
            WakelockHelper.acquireCpuWakeLock(c); //WAKELOCK TRY
            Log.d("Screen off", "Screen off"); //OUTPUT OK
            Intent s = new Intent(c, ActionService.class);
            s.putExtra("LVL", lastBatteryLevel);
            c.startService(s); //NOT CALLED
        }

and to release it after the preference is saved. But this doesn't change anything.

Just to be complete, here's my WakelockHelper class

public class WakelockHelper {

    private static PowerManager.WakeLock sCpuWakeLock;

    static void acquireCpuWakeLock(Context context) {

        if (sCpuWakeLock != null) {
            return;
        }
        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);


        sCpuWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,"Tag");
        sCpuWakeLock.acquire();
        Log.i("Wakelock", "Wakelock set");
    }

    static void releaseCpuLock() {
        if (sCpuWakeLock != null) {
            sCpuWakeLock.release();
            sCpuWakeLock = null;
            Log.i("Wakelock", "Wakelock released");
        }
    }

}

So, how can I save the current battery level when the user locks the phone? Why is my service not started after the screen-off intent? Why doesn't the wakelock change anything?

Thanks!

OUCH... Forgot to declare the ActionService in the manifest :O