RE: battery lifetimes...
Hi,
As GGJstudios points out in the link, battery lifetimes depends upon many factors, including precisely what websites you visit. Personally, I get anywhere from 4 hours to 7 hours on battery power for days that I consider to be my "average" workload. So I report my battery lifetimes as 5.5+-1.5 hours for my average battery lifetime plus variance. Getting just 4-5 hours of battery life does not indicate a battery problem, it just means that your workload uses battery power more quickly than someone that gets 5-6 hours. Maybe you watch more flash videos, perhaps you visit websites with more flash advertisements, maybe ...
In conclusion, just because someone else gets 7 hours of battery lifetime does not mean that you should also get 7 hours of battery lifetime ... it all depends upon precisely what you do, what apps you run, what computations you perform in those apps, whether spotlight is indexing your drives, what sites you visit in your web browser, etc.
Regards,
Switon