Q: Why does my Macbook Pro Retina's battery drain so quickly?

Okay so I have Mavericks for my Macbook Pro retina ( I have been hesitant to update to Yosemite because I heard connecting to wifi takes longer and it slows down the laptop but at this point if it improves my laptop's battery life I might update anyway..). It is only about a year old I got it December of  2013. Lately I have been noticing that my laptop's battery has been draining so easily. It usually lasts about 4-5 hours (even thought ideally it would last about 7) but these days it has been lasting me barely 2 hours. How can I fix this? Will quitting applications like Google Chrome make it any better? Are there any apps or anything I can install that can help in extending my Mac's current battery life? Please, help. I really need my battery life to be way better than this :/

Thank you.