My Lumia 930 updated to the latest slow branch insider preview build last friday and since then it has been running through the battery a lot faster than before and runs a bit warmer than before even when it's on idle. At first I thought it was because of my recent data plan upgrade from 3G to 4G but when I forced the connection down to 3G it still drains battery like crazy. So is this a known problem or is something else messed up on my phone? And if so, are there ways to fix this?
A hard reset solved the battery issue. Now the build is running all fine and dandy!
Don't worry, that's a common issue. That is why preview builds are. To point out bugs and problems to Microsoft. Make sure you give a feedback, it might be useful. By the way, the latest Redstone build, 14322.1000 is so far the best version of Windows 10, you should update!
Battery usagein Parameters->System->Battery Saver. – Niki-Timofe Apr 13 '16 at 20:16