realme
Luckily, the system restrictions are all gathered at one place in the system settings in the Battery section, and also have some description there.


Power saving options
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Power saving mode - reduces screen brightness, changes auto screen-off time to 15s and disables background sync.
Can be set to launch automatically at a set battery level.
It may terminate background processes. -
Super power saving mode - extra saving option, allows you to have at most 6 apps to use.
It will disrupt background processes.
App battery management

2. Choose the app from the list.

On newer versions, the App battery management was moved to system settings → Battery → Power saving settings → App battery management.


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Allow auto-launch
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Allow foreground activity
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Allow background activity
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Optimize battery use


Power saver options


- Sleep stand-by optimization - automatically enables low power mode when the system thinks you are asleep.
Performance mode


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High-performance - consumes more power, mode for online gaming for example
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Smart Performance Mode - optimized mode depending on the workload, may break background processes
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No Performance Improvement - no additional boost of performance
App quick freeze
- Casts a ‘freeze’ spell the apps from this list - they cannot receive or send notifications and cannot run on the background.