Q: Macbook Air Battery Drainage

I just recently bought myself a 13" Macbook air from Best Buy brand new. I have had it for almost 4 days now. I bought it to use at school.

The first day i used it i noticed that the battery was draining very fast (2% every 5 minutes on a full battery). I thought maybe because it was new i needed to get the computer used to it so i kept it charging over night. The next day it was still draining about 2% every 5-7 minutes on a full battery. I am confused because i thought the Macbook air should last longer that that.

Yes i keep my back lights off, i turn off bluetooth, i only keep the brightness on 4 notches only.

I am wondering if there is something i should do or if i should take it back to Best Buy.

P.S.

The Battery drained from 100% when i was typing this, it took me about 4 minutes to type and my battery percentage is now 89% saying i only have 5 hours left of usage.