rMBP Battery bug?

Yeah so I noticed this battery bug on my brand new 13" rMBP (less than a month from when I bought it). I came across this problem when I was experiencing rather unusual battery life, my laptop has never lasted more than 7 hours. I know the advertised battery life is without the use of flash content etc. so one day I used my MBP only on Safari and spent almost all of the time on wikipedia. It was boring but still the battery didn't last more than 7 hours. Today I tried the PRAM reset and I noticed that the battery % that OS X shows differs from what the app coconut battery shows. First I thought the app was wrong, so I went in to system information and did the calculation myself, turns out OS X was wrong.

The picture shows that while OS X shows 87%, the app shows about 82% (which is mathematically correct). Since the OS X % is an estimation I'm not too worried but should I be?

Also notice how, with 14 cycles, a good battery health and at 87%, my estimated time remaining is at 6:14. I only have Safari open with one tab - the one I'm using to open this discussion.

I tried resizing the image but it was messing with the text, so sorry about that 😟