Automatically update widget when battery percentage change

Question

I'm trying to get my widget to update when my battery percentage change. Iv'e solved for when i press the widget so it updates but that kind of ruins it for me. It updates by default every 30min. I don't want it to change after a period of time but when my battery goes down or if charge- going up. Also is it possible to change the color of a shape with code? I have a percentage ring I would like to change when battery is down by say 50% or so.

import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.util.Log;
import android.widget.RemoteViews;


public class Battery extends AppWidgetProvider {

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] 
    appWidgetsIds) {

        ComponentName newWidget = new ComponentName(context, BlueTooth.class);
        
        int[] widgetId = appWidgetManager.getAppWidgetIds(newWidget);
            String name = "My Phone";

            IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
            Intent batteryStatus = context.registerReceiver(null, ifilter);
            assert batteryStatus != null;
            int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
            int scale = batteryStatus.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
            int batteryPct = level * 100 / scale;

            RemoteViews remoteViews = new RemoteViews(context.getPackageName(),
                    R.layout.blue_tooth);
            Log.w("Percentage", String.valueOf(batteryPct));

            remoteViews.setTextViewText(R.id.percent, (batteryPct) + "%");
            remoteViews.setTextViewText(R.id.update, name);

            Intent intent = new Intent(context, BlueTooth.class);
            intent.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
            intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, appWidgetsIds);

            PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 
            PendingIntent.FLAG_UPDATE_CURRENT);

            remoteViews.setOnClickPendingIntent(R.id.percent, pendingIntent);
            remoteViews.setOnClickPendingIntent(R.id.update, pendingIntent);
            appWidgetManager.updateAppWidget(widgetId, remoteViews);
        }
    }

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="ring"
android:innerRadius="25dp"
android:thickness="3dp"
android:useLevel="false"
>
<gradient
    android:endColor="#3CB371"
    android:type="radial"
    android:useLevel="false"
    />
</shape>