Lumia 520 - Battery discharges rather quickly.

[alinauman97]

Hey guys. I have a Lumia 520 (RM-914), which has been in use since June 2013. In August of last year, I noticed that the battery had started to discharge rather quickly. It would discharge at a rate of about 7-8% per hour without usage. Then last night, I got a new battery, but it drains almost just as fast. Any ideas what's happening here?