Marshmallow drains my Nexus 5 battery - SOLVED!

After upgrading to 6.0.1, my battery drains fast.  The fully charged Nexus 5 would only last for 8 hours and I have to recharge. This is on a normal day when I would use the phone occasionally to check email and web browsing.

The problem seem to be common after searching the web and the sympton being you would notice Wifi is consuming major power even if you have not turned it on.

http://forum.xda-developers.com/google-nexus-5/help/wifi-plaguing-android-marshmallow-t3220031

The fault seem to be by designed. Google has overlooked how much power wifi could consume.  Turning wifi scanning in the Location setting may help.

I just turned it off now. Don't know the effect yet but I hope this solves the problem. Another example of non-thoughtful design!


Updated 16-Jan-2016: installed the latest Jan security patch and problem remain.

Updated 17-Jan-2016: disabled the location service to use wifi and always rely on GPS. This solved the problem for me. This is annoying. I think it shall also work if I turned off the location services altogether.