I never updated to Lollipop. Still on KK 4.4.4.It's Lollipop. Ever since I upgraded to Lollipop my phone drains to 50% using WiFi within less than 2 hours of internet browsing. I've done every suggestion including factory reset but still fast battery drain. I'm going to spend about $8 on a new factory battery on Amazon and see if it makes a difference. I would prefer not to get a new phone yet although I love that S6 Edge look!