Exclamation 7hr Battery DRAIN! [Battery issue]

Hi guys, like the title says I've got a battery issue!
About a month ago I bought this amazing nexus 5 device for a great deal 275 for the phone that is in great condition + a Chinese brand charger. The problem Is the battery I made a screenshot of the battery time only thing I used was Spotify and the brightness was on auto. This is deffenitly a problem! What should I do?? Should I buy a new charger and battery and flash a custom kernel like Franco's to save some battery? Thank you for reading guys
Attached Thumbnails
Click image for larger version

Name:	Screenshot_2014-03-10-21-10-50.jpg
Views:	3317
Size:	120.0 KB
ID:	2624510