Battery draining fast on Galaxy phones and tablets

1. First, close all running apps. Tap the Recents icon to the left of the Home button to view all of your active or opened apps, and then tap Close all.
   
   Note: If you've customized your Navigation bar, Recents may be located on the right, unless you're using full screen gestures.
   
   
2. Next, optimize your device. Go to Settings, tap Device Care, and then tap Optimize now. If Device Care determines that your device is already in great condition, you cannot optimize it.
3. Disable push notifications for apps you don't use or want notifications from. Navigate to Settings, tap Notifications, and then tap App Notifications. Then, turn off the switch next to the app.

Navigate to and open Settings, tap Battery, then scroll down to the graph and tap View details to review information about app usage. 

• Turn on Power saving mode to decrease your phone’s performance. Tap Power saving, and then turn on the switches next to your desired settings. 
• Put rarely used apps to sleep in the background to avoid battery drainage. Tap Background usage limits, and then adjust the following settings:
  • Put unused apps to sleep will automatically put apps to sleep if they have not been used for a while.
  • Never auto sleeping apps allow you to choose which apps will not automatically be set to sleeping mode.
  • Sleeping apps allow you to choose the apps that won't run in the background. You can view your current sleeping apps as well.
  • Deep sleeping apps will never run in the background and will only work when you open them.
• Switch to Light performance profile to prioritize battery life over processing speed. Navigate to and tap Settings, tap Device care, and then tap Performance profile. Select Light.

Navigate to and open Settings, tap Display, and then adjust Select desired option to reduce power consumption:  

• Tap Dark mode to turn on a darker color scheme, and reduce eye strain. To set a schedule, tap Dark mode settings, then turn on the switch next to Turn on as scheduled.
• Drag the Brightness slider to the left to manually lower your screen brightness. Alternatively, you can turn on the switch next to Adaptive brightness to let your device learn your usage patterns and automatically adjust the screen's brightness.
• Tap Motion smoothness and then tap Standard to reduce the screen refresh rate up to 60 Hz.
• Turn on the switch next to Eye comfort shield to reduce blue light emission. 
• Tap Screen timeout, and then select a shorter time to automatically turn off the display after a certain period of inactivity.
• Turn on the switch next to Accidental touch protection to protect your phone from accidental touches when it's in a dark place like your pocket or bag.

Navigate to and open Settings, tap Lock screen and AOD, and then turn off the switch at the top of the screen to disable the feature. Or, tap When to show and choose one of the following: 

• Auto: Show all the time unless your phone detects that you’re in a dark area or it’s placed in a purse or pocket.
• Tap to show: Always On Display will appear for a short time after tapping the screen.
• As scheduled: You can set up a schedule for when Always On Display will display. For example, you can make it display during the day.
• For new notifications: Always On Display will be shown briefly when a new notification is received.