For windows I can recommend to got into the power-settings and change the Maximum % Value for the CPU from 100% to about 66%.
You won´t feel any disadvantages in normal surfing and working. But the CPU wont fire up to 100% for every click you do. It´s about miliseconds.

I used this for my Dell Notebook and got from about 5h to almost 8h while working.
Of course I played a bit around with the values. At about 40% I start to feel some lags. But while writing in Word or posting on Steemit it works great and saves a lot of power.

And with Windows-Key + X --> M you get directly to the Mobile-Center and you can adjust the powersetting with only two clicks.