Nexus 4 draining battery while charging and in use

[CMac o]

I have a new battery and all in my nexus 4. While i was watching netflix the phone was plugged in from the wall and i saw after half an hour of watching netflix the battery went from 15% to 14%. I rebooted the phone a few times to confirm there was no mistake. Im conserned. Not only that but charging is incredibly slow despite the official nexus 4 charger i'm using and terrible battery life. I installed cyangenmod 10.2.1 with MultiRom and the battery life is extended, but not extended enough. Its very annoying :S
(It charges just fine when left locked but still very slow)
Thanks

Cormac