Currently Being ModeratedJul 29, 2012 7:02 PM (in response to JavaLink)
I would check for a Software update in the upper left under the Apple menu. If there is nothing or it does not fix your problem, then I would try installing Mountain Lion fresh.
You could backup your Air with Time Capsule or Carbon Copy Cloner (just a couple of ways to do it). To reinstall you would hold option as you power your Mac up. From here you would want to select a fresh install (I can't remember the exact wording).
I have a 2011 MacBook Air and, even with several fresh installs of Lion, Mountain Lion blows Lion away with battery life. Theoretically, with a newer Air and Intel's advancements in battery, you should get very good battery life on your new Air. I have noticed that Mountain Lion has substantially better battery life while sleeping in particular.
Currently Being ModeratedJul 29, 2012 7:32 PM (in response to JavaLink)
It sounds like a runaway process of some sort.
If you run Activity Monitor, does it show anything chewing up CPU cycles? That can give a clue as to what the issue is and, perhaps, how to solve it.
Currently Being ModeratedJul 30, 2012 10:20 AM (in response to JavaLink)
I discovered the problem today. I have a microsoft / mac program which syncs outlook to various sources. This program was corrupted when Mountain Lion was installed. As a consequence, the program was compounding its use of the airbook's memory - some 2GB of memory used in less than 5 minutes.
Once the program, called sync services agents was repaired, the problem went away.
I hope this information is helpful to someone.
Monitoring the Activity Monitor was the key to the diagnosis!