The Marshmallow Update has destroyed my battery life ... !!! Before the update I was getting 1-2 days (24-48 hours, even 12 hours with heavy use, and some battery remaining) with my ZeroLemon 10000mAh Extended battery. Now I get around 7-8 hours total from 100% to Zero %, which is terrible, and totally NOT acceptable. I'm hoping there will be a fix for this major bug/glitch soon ...... I use my Note 4 for heavy gaming, sometimes all night long. I need to enable Bluetooth, full Brightness, Tethering, GPS, and have several apps open at the same time. I was still getting a full night of heavy use from around 7:00 p.m. until 10:00 a.m. the next day, with battery power still remaining. Now, I need to have my Note 4 connected to one of my battery packs, which is a very inconvenient ..... Oh yes, I did the Factory Reset, which did NOT help at all. Everything is exactly the same as before (same apps, same settings). I actually have less apps installed now. I have turned off everything that I can (haptic feedback, sounds, notifications, animations, etc.). But I must have Bluetooth, Tethering, GPS, Roaming (to maintain a solid Internet connection for gaming > Ingress), and full Brightness, which was not a problem with Lollipop.