brand new, fully-charged MBA 11 only shows 3 hours of battery life

[arrowtree]

I got my MBA 11 this morning. First thing I did was plugging in the charge.
A few hours later, I powered it on for the first time.

After using it for about an hour, I noticed the battery life was showing
3 hours remianing. The brightness is set to slightly less than 50%.

All I've done was browsing the internet using Safari and figuring out
how the Mac OS works. Nothing that I would consider CPU or SSD
intensive usage.

I shut it down again around 5:00pm and plugged the charger back in.
Just turned it back on again around 7:30pm. It's been sitting there
for 15 minutes. The battery remaining time now shows a a little over
4 hours.

Is this normal? Or will it go up after several charge/discharge cycles?
Obviously I know it's not going anywhere near the 9 hours claimed
by Apple... but 3 or 4 hours on a full charge seems awfully short to me.

 

[yosemit]

It's normal. Won't be surprised if the meter shows 3 hours and the actual is 8-9 hours.

By the way, a new mac may run some intensive background jobs like building index or updating the OS.