The Nexus 6 for the most part will get you a day to a day and a half of battery life which when you compare it to the Nexus one is back to square one. For us to have add some many additions such as a larger Quad HD display, quad core, and running on LTE to have come full circle where it can go 18 hours is a great feat. Considering how we used our phones then to how we use them now (gone from a messaging device to an addiction) I do not think the issue is mainly manufacturers are behind the time with battery tech. But we as a society can not put our phones down. It has become epidemic now driving and seeing people looking down at their facebook/twitter pages while driving 60+mph vs paying attention to the road. From the time we wake up until the time we sleep some of us spend more time with our phones then out family members. Not preaching to you just thinking that maybe just maybe the standards of comparing phone battery life now to battery life in the past is more of rose colored glasses. Yeah a flip phone could last weeks on a charge but we also only pulled those out to make a call and not to watch videos or keep up with our social status. And the 3g phones of the past were in an era where social media started up but was not as widely used. Now companies hire people just to keep their social network pages up to date.
So are our demands for more battery life reasonable or do we need to step back and look at how much time we spend on our phones?