Use Low Power Mode to save battery life on your iPhone or iPad

With the approach and impact of Ian it might be timely  to learn about Low Power Mode. …Low Power Mode reduces the amount of power that your iPhone or iPad uses when the battery gets low.
To turn Low Power Mode on or off, go to Settings > Battery. You can also turn Low Power Mode on and off from Control Center. Go to Settings > Control Center > Customize Controls, then select Low Power Mode to add it to Control Center. Read more