My laptop is just 2 months old, I give it normal use because I have other 2 PC's , and after installing Evernote desktop, I noticed the battery draining issue...
(also this issue seems to be present in the windows version as well, as my dell laptop also shows high cpu usage when Evernote desktop is running)
So I don't think that the battery damage is caused by used or bad charging habits ( I also have enabled smart charge)