[Q] Battery dying pretty quickly while charging topic

I switched to CM12 about a week ago, and it's been fantastic. I use a lot fewer apps now as well since I cleaned up what I had installed/running when I made the switch. Now, however, my battery will drain really quickly when I have it charging and I'm doing anything else at the same time. For example, I currently have it plugged in to the wall and I've been watching some YouTube videos. In the past 15 minutes I've gone from 15% to 7% battery. Titanium Backup is running a batch backup in the background as well, but I experience this problem whether TiBu is running or not.

I'm using the power plug that came with the phone but the actual USB cord is from my Chromecast. (The cord shouldn't matter though, only the power adapter itself.)

Does anyone have any ideas? I do keep CM12 updated with the latest nightlies.