BATTERY_PROPERTY returns 0

Question

I'm making a app based on BatteryManager. But every BATTERY_PROPERTY returns 0. Here's my code:

     if(Build.VERSION.SDK_INT >=21){
     BatteryManager bm = (BatteryManager) MainActivity.this.getSystemService(Context.BATTERY_SERVICE);

        int remainingCapacityRatio = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY);
               //print it
        int batteryCapacityMicroAh = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CHARGE_COUNTER);
                //print it
        int dischargingTimeSeconds  = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CURRENT_AVERAGE);
                //print it
        int  currentNow  = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CURRENT_NOW);
                //print it
        long energyCounter  = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_ENERGY_COUNTER);
                //print it
            }

Even I use getLongProperty(), I only get a fixed value.

I do have the BATTERY_STATS permission (and Intent.ACTION_BATTERY_CHANGED, even though it doesn't need it).

And one more thing: Can anybody tell me how can i get the current battery capacity (current, not total)? Can my code above do it?

Edit 1: The first one (remainingCapacityRatio) works, but i need the other 4 more!

Edit 2: There was a guy who ask the same question (Android BatteryManager returning 0 for all property-retrieval calls), but he didn't get the answer he wanted!