Get Battery info on Android

You can get (or you can say moniter) battery event by register battery intent.

registerReceiver(mBatInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
mBatInfoReceiver = new BroadcastReceiver(){
            @Override
            public void onReceive(Context arg0, Intent intent) {
                int level = intent.getIntExtra("level", 0);
            }
        };

Don’t forget to unregister your broadcast receiver:

unregisterReceiver(mBatInfoReceiver);

There are further intents you can moniter:

filter.addAction(Intent.ACTION_BATTERY_LOW);

filter.addAction(Intent.ACTION_BATTERY_OKAY);

filter.addAction(Intent.ACTION_POWER_CONNECTED);

filter.addAction(Intent.ACTION_POWER_DISCONNECTED);

Please notice that Battery Okey is the intent when device leave low battery mode.