Nexus 7 charging/battery consumption problems
I recently bought a first-generation Nexus 7 and am having some problems with charing/discharging/battery consumption. Right now, the problem appears to be that the device charges painfully slowly when the screen is turned on. The device has literally been plugged in to the factory wall charger (12V 2A) for more than 5 hours, and the battery level has increased from 70% (when it started) to 74%. During this time the screen has been turned on, brightness to the lowest setting, airplane mode on, and no apps whatsoever are running in the background.
However, it appears to charge at a normal speed when the screen is turned off.
I have also noticed that when apps are running (not battery intensive apps, either--basic web browser, maps, etc.) while the screen brightness is at 100%, the battery actually discharges when the device is plugged in.
It's rooted and running a cyanogenmod 4.4 ROM.
Any help would be appreciated.
Also, I have been testing with the screen turned on because I'm using this tablet for an application that requires the screen to always be on.