Ever since Google released the Developer Preview of Android N, we've all been looking forward to seeing what future versions of the preview would bring to the table. We didn't have long to wait, as the second preview of N was released not too long ago, and for the most part brings a handful of visible changes and many more smaller changes. One of which appears to be a change to the way that folders look in the default launcher, something not everyone is in agreement on. Of course, as this is a Developer Preview, it's unsurprising to see this second release of N launch with a few bugs, one of which seems more of an oversight than anything else.
For some time now, stock Android has had a pretty technical detailed history view of what's been sipping - or sucking - away at your battery, but in the new version of Android N, Developer Preview 2, it's just not there. If you go looking for it while running the new version, you won't see any of the usual detailed information below the fancy graph, there's just a larger graph and nothing else there. That means that there's no data to let users know how much battery life was surrendered to WiFi, how much went to GPS and so on. Apparently, this is going to make a return in the next version of the Android N developer preview, as bug reports pointing out the issue are apparently being removed as it's already going to be addressed.
This is a small bug, and considering the point of developer previews - to be used on non-essential hardware - this shouldn't affect too many users. At the very least, this is a good way of reminding people that these previews of the next version of Android aren't designed to be used as a daily driver, and while this is unfortunate for those looking to see if their app or game is kind or not on a user's battery, it's coming back in the next version, so there's ultimately not much to worry about here. Long story short; dev previews aren't for everyday use.