The android system is eating up my battery, I can see my battery drop like 15/20% while I'm just browser on the internet with just 5minutes of use
I am having the same horrible battery life since the Kit Kat update. If my memory serves me correctly, I had the same problem when updated to Jelly Bean. The only solution that fixed it was a full restore/reset. It's one of those things I hate doing because of he process of reinstalling/tweaking the phone to my specific liking.
Spending this evening to back up all my info, photos, and other data. I will be doing full reset sometime tomorrow. I'll check in later in the week and let you know if that solves the problem.