MainActivity.java

    private void checkBatteryState(List<Sensor> sensors) {
        for (Sensor sensor : sensors) {
            if (sensor.batteryNeedRecharge()) {
                sendNotification(sensor);
            }
        }
    }

    private void sendNotification(Sensor sensor) {
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.drawable.ic_battery)
                .setContentTitle(getString(R.string.notification_title))
                .setContentText(sensor.getLabel() + getString(R.string.notification_text))
                .setAutoCancel(true)
                .setOngoing(false);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
        notificationManager.notify((int) sensor.getId(), mBuilder.build());
    }