User manual
it is most needed.
To enable Smart Power Saver, go to [Settings] > [Battery] > toggle [Smart Power
Saver (Recommended)] to green to enable.
When Optimization is needed
When issue or issues are found, then it will prompt you that optimization is
recommended. Just click on Save Power and check those that needed optimization,
click Lengthen Battery Life, and then click Done when finished. (Note: Expected
usage will be shown but this still depends on the usage and running apps on the
background).