or want to automate this mode when screen is off as in this simple example where after 40 mins the mode will be activated
There are screenshots in post #2 step by step
First u need sense 6 rom and of cos u need to be rooted
U need "Llama" and "Secure settings" both being free apps from playstore
i am using Llama as its easier to use
1) Just open llama , new event
2) add condition as screen off ( with delayed event 40 mins) , choose action , local plugin, secure settings , options , launch activity , power , choose app first, then choose from dropdown list [Power].extremepowersaver.Extremepowersaveractivityconfir m ( if u can see the words being too long just tilt and use landscape mode)
Save yr llama event. thats it.