If the "it" you are referring to is the menu bar, I find that mine sometimes takes forever just to calibrate itself correctly. I use coconutBattery app or the iStat widget.
From 0 - 100%, it took 5 hours.
Right now, at 94%, I'm reading 19 minutes to be totally recharged. (Originally at 95%, I read that it was entirely charged, so I brought it down to 94. Now at 95 it says 16 minutes. But I'm also on the Internet (obviously) and typing so whatever other activity you're doing also will impact charging time. I guess so would how you set your energy saving prefs.
I'm usually in sleep mode and drain/calibrate once a week.