Android : Do something when battery is at a defined level

Question

I\'m stuck with a little problem here.

I want my app to do something, but only when the battery is at 10%.

My app doesn\'t watch the battery level constantly;

Answer 1

ACTION_BATTERY_LOW doesn't have the Extras you're trying to read from it, so you're getting percent as -1 every time.

As @bimal hinted at, those Extras are attached to the ACTION_BATTERY_CHANGED Broadcast. That doesn't mean, however, that you should just register to receive that instead. ACTION_BATTERY_CHANGED is sticky, so registerReceiver() returns the last Intent immediately. That means you can do something like:

public void onReceive(Context context, Intent intent) {
    if(intent.getAction().equals(ACTION_BATTERY_LOW)) {
        IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        Intent batteryStatus = context.registerReceiver(null, ifilter);

        int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
        int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, 100);
        int percent = (level*100)/scale; 

        if (percent <= 10 && percent > 5) {
            // Do Something
        }
    }
}

Note that registerReciever() was called with a null BroadcastReceiver, so you don't have to worry about unregistering. This is a nice, clean way to just say "What is the battery status right now?" (Well, technically, it's what was it last time a Broadcast was sent.)