Many of us are facing a problem too much that we can not save battery life of our android mobile phone. It is too much disturb us everyday. But today I am trying to give a solution for it. I think if you try this, you will be able to save your battery life more from before.
The main problem is that when you open an app and after complete your need you close that. But in android versions that app do not completely stop after closing. It is working though you completely close it. Though you do not find that app open but it is consuming your battery.
Google android developer may be try to reduce this problem at higher versions but I think they could not be successful completely. And for that you can not save your battery life.
If you want to save your battery life you must use "Greenify" app to hibernate the background apps and you will get it from google play store. It will be an effective solution I think.