mid-2013 MBA 11' battery drains when complete shut down

hey guys i've recently purchased a mid-2013 model of MBA for leisure use (webpages etc.), and i came to notice that the battery will drain even the computer is completely shuts down. For experiment sake i fully charged it the other night, turned down the computer, wait for a day(adapter disconnected), the next night i turned it back on the battery drops to 86%. I didnt installed many softwares in it yet except Microsoft Office 2011, and i use build-in Safari to surf the web instead of Chrome. Currently the fully charge capacity is at 4905 mAh, 5 circles.

what makes it weird is if i chose to put the computer to sleep instead of shutting it down, for overnight the battery drops max. 1-2%. other than this i dont have any complaint on the battery life - 6-7 hours under normal usage.

anyone experience same situation or knows how to fix it?

many thanks in advance