There are several things that you can try to do to try and eliminate battery drain on your cell phone. Android phones have several settings that can be turned on to lower battery usage.

Power Saver Mode

Enabling power saving mode will reduce background network usage, syncing and location checking.  It will automatically reduce the brightness of your screen, the CPU usage will drop to 70% and the display will turn off automatically after the display timeout time.

1. Slide down from the top of the screen & tap the gear icon
2. Scroll down to Device Care or Battery & Device Care
3. Tap on Battery
4. Tap the On/Off button for Power Saving mode

Adjust Screen Brightness

Next thing to do would be to adjust your screen brightness - Adaptive brightness will spike the battery usage as it forces the screen brighter depending on the ambient light.
You can also adjust what the ‘normal’ brightness level is by adjusting the contrast bar on the phone’s display settings.

1. Slide down from the top of your screen and use the brightness slider
2. Tap on the 3 dots on the right to access the Adaptive Brightness option.

Dark mode

Setting your phone to dark mode will reduce the brightness necessary to display the screen and reduce the battery drain the screen takes. 

1. Slide down from the top of your screen and tap the settings gear
2. Tap on Display
3. Set the phone to Dark Mode

Background Usage Limits

Even when apps are not in use they can still run automated processes in the background.  This can use battery life and data at the same time.  Going into the battery settings you can tap on an app and limit its usage.

1. Slide down from the top of the screen & tap the gear icon
2. Scroll down to Device Care or Battery & Device Care
3. Tap on Battery
4. Tap on Background Usage Limits & enable put unused apps to sleep
5. Tap the back button to go back to battery usage
6. Scroll down to the apps and tap on individual apps
7. Tap on Limit Usage