Battery Issue with Android 6.0 I upgraded my Karbonn Sparkle V to Android 6.0 recently. after a couple of days the battery drains quickly. hence charging the phone also takes hours. this was not at all a issue when it had lollipop 5.1.1. 

yesterday the battery was 54% at night 12:00. closed the web browser, all apps, locked the phone as usual and slept but in the morning when I saw it had 4% battery remaining. 

when I saw battery settings morning 4 new menus displayed, apart from display(6% usage) and chrome(4% usage), viz. Phone Idle, Wi-Fi, Android OS, mobile signal. they all used 1% of battery each. what might be the problem. Wi-Fi was always on from the day1 of purchasing the phone no issues at that time. only now issue arises. what might be the problem?

and I saw this post(Android 6.0 drains my Nexus 5 battery within an hour).
It only changes settings and display like a new one but battery issue is same.
The Marshmallow 6.0.1 update seems to have solved this battery drain problem.

Source: AndroidPit

2 users have confirmed it in that link. Please check.