Turn on Auto-brightness or manually lower the screen brightness. The number one reason of iPhone battery depletion is usually the screen brightness. As a result, it's best to keep your device's screen brightness at a minimum.

Disable dynamic backgrounds and motion effects. You may conserve some battery life by adjusting the app settings on your iPhone to reduce the frequency of app and widget updates. When you delete any applications from your iPhone that you aren't using, the same thing happens. Even when they're not open, background-running apps and widgets consume a substantial amount of power.

When not in use, turn off connectivity options such as Wi-Fi and Bluetooth. Because they frequently look for connections, wireless connectivity capabilities such as Bluetooth, Wi-Fi, Mobile Hotspot, and GPS (location services) might have an influence on the battery when they are active. As a result, turning these functions off while not in use might help your iPhone last longer. If Wi-Fi is available, choose it over an LTE connection (Cellular Data) since Wi-Fi uses less power. These settings may be turned off in the Control Center or by going to the Settings menu on your iPhone 8 Plus. Just remember to enable them when you're ready to use them again.