I noticed that all the battery life information on the Apple Mac Book products line has been updated. I remember previously they have listed the battery life of a MacBook Air is 10 hours. However, ever since their Battery Problem on Lion, a lot of reports/complaints about battery life. What happened now after they released 10.7.3?? IMO, They are unable to fix the battery problem, but changed their product spec from 10 hours to 7 hours.
I have downloaded the 10.7.3 on my 2011 MBP, when I was using 10.6.8, I could easily get 7 – 8 hours of battery life. After installed the 10.7 (Lion), my battery life dropped to 2 hours only. And then after applying the SMC reset fix, it can last up to 5 hours.
I am testing it with 10.7.3 with 50% brightness, fully charged, 1 hour of web browsing on WiFi, it dropped 15%. So 10.7.3 can improve a little bit of battery life. In my test, it can run for approximately 7 hours.
There are a lot discussions on the net about this Lion Battery Problem. Someone even test this by re-installing the OS, compare SL and Lion. In all the tests people have done, Lion uses more power and need more battery. I think this may be one of the reason, Apple updated the web site, MBA battery from 10hours down to 7hours (due to the bad Lion OS).