Dwindling Note 2 Battery Life - What Gives?

I'm a proud owner of the Note 2 (AT&T), and I've been noticing that the battery life has slowly gotten weaker. Where it once felt like I had to try to drain the battery, it now feels like I have to try to make it a full day.

I'm not a power user by any means - I use my phone on a daily basis to make phone calls (about an hour a day), email, and browse the web. Since I'm a teacher, I go hours without using my phone and have been getting into the habit of putting it on airplane mode to stop data - but even if I do my battery drains 8% after 2.5 hours!

The battery that I currently have in is a few month old Anker, but even the new battery didn't extend the endurance of my phone. I'm hoping that the 4.4 update will help extend battery life, because it's going to be a frustrating couple of months if it doesn't improve things (my contract goes up in November).

Has anyone experienced similar battery loss, and if so, are there any improvements or workarounds that you've found to be helpful?