Thought I would add my 2 pence worth regarding hungary massive battery consumption after the Marshmallow update. Before the update, my battery was amazing and it was noticeably better than my old S4. I didn't need Greenify or doze and I didn't need to turn off Google location in apps.
Then the Marshmallow update came along and it was instantly noticeable that the battery was draining much faster since the update. One night I forgot to plug my phone in to charge and it dropped from around 50% to 15% overnight. I tried apps, like the ones mentioned above to stop apps using the network when my phone is in standby. Nothing seemed to help. One app that did help was GSam battery monitor, I could see my phone radio was using 30-40% battery.
Anyway, after a couple of factory resets and deleting the system cache partition, I noticed that things would be fine for a day or so before nose diving. I noticed that after Samsung apps updated which included updates to the edge screen, the troubles would begin. After my last factory reset, I immediately turned off the edge screen updates and uninstalled Samsung apps. I am now using 3% radio with 20.27 hours usage and the screen is now the biggest hog of battery, which is to be expected.
Much, much better battery now