Stamina Mode on Sony Xperia E1

Sony xperia e1 comes with built in stamina mode feature, what is stamina mode? how does it work? how to enable it?

Stamina mode is a sony's power save function. It extends battery lifetime by disabling functionality while the screen is off.

When the screen is off, all network data will be disabled temporarily, and most of your applications will be inactive, to save battery.

When the screen is on, your device will function normally. Stamina mode is disable by default, to enable go to Settings > Power management > turn on STAMINA mode.

If you want to keep some apps active when the screen is off, just add them to the APPS ACTIVE IN STANDBY list.

NOTE :

some applications may not work properly when disabled in standby. If an application does not work properly, add it to the APPS ACTIVE IN STANDBY list, or if this does not work, deactivate/disable stamina mode.