Retina Macbook Pro now has faster battery drain I have disabled Hibernation mode and Deep Sleep mode, I also keep the charger plugged in about a week before removing it if I want to go somewhere with the laptop.

I don't know if this is normal, but I realised that my battery started draining faster recently. I usually have 6-8 hours of time on battery for web-browsing, youtubing, a bit of programming and nothing really power intensive. GFX-status usually displays i for integrated GPU usage. However I recently started getting 4-5 hours maximum. 

Why is this happening ? is it the lifetime of the battery starting to decrease ? I purchased this laptop over summer (one the first batches the retina macbooks were released). So it's not really that old. Can anyone provide a possible explanation to this phenomenon ?
Reboot.
Create a new user.
Try.

If the battery life is still short after a couple of days under a new account and there's nothing weird. Take it back to an Apple store. They will run the hardware test and determine if there's a problem with the battery. Be nice to them. Explain them that you know what you're doing, that this is unusual, that you know how to take care of a battery, that it suddenly started happening and that you would like for a Genius to take a look at it. 

I did that with my Macbook Air 11 (with a 8 month old battery that just died out of nowhere) and they kindly replaced it. 

Better safe than sorry.