I have had my 1.2GHz rMB for about a week now. I am absolutely loving it so far!
However, I am only seeing about 5-6 hours of battery life doing very normal web browsing, email, itunes tasks. Apple claims I should be getting around 9 hours.
I am running OS X 10.10.4. I did not migrate my machine from a previous backup, it was a clean install. I have checked the activity monitor, and nothing seems to be eating up a lot of power.
Have other people been experience this amount of battery life?
Under light use (WiFi browsing and email using Safari with ClickToFlash and AdBlock) and at about 50% brightness I'm getting the 9 hours Apple claims. Processor sits at 1-2% with bursts up to about 30% (when scrolling etc) and temps are in the 40-50C range.
But the power management on these machines is so highly tuned, it doesn't take much to make a huge difference. Under "normal" use (WiFi Browsing, Background music playing, email, MS Office apps, some DB work, occasional blips for Time Machine, Dropbox etc and brightness at around 75%), I'm seeing 6 hours or a bit more. Processor sits at 5%-75%, temps usually in the 50-60C range.
Under heavy use (Cpu in the 30%-90% range, Temps hovering in the 70's) my battery range is more like 4-5 hours. Overall rMB battery life for me is better than my MBA, just a little for heavy use, and extending its lead as usage drops.
Things like using Chrome, or not using utilities like ClickToFlash and AdBlock, screen brightness, quality of WiFi signal, Transparency settings, background programs running (spotlight, time machine, dropbox, AV, pandora, itunes...), battery health, screen resolution, etc can make a big difference. Looking at Power usage in Activity monitor can sometimes help but not always as a lot of little things can add up. Run through all your system settings for anything that might impact CPU usage, paw through all your startup items and launch daemons to make sure nothing you don't need is there, think about usage patters like keeping an idle app open vs stopping and restarting it a number of times through the day. There is often a lot you can do.
As an early adopter of the very first MacBook Air and a user of many models since, I've learned a lot of optimization tricks that I continued to use over the years. They got less impactful with each generation of the Air, but I think I'm reaping some rewards with the rMB now.
Good luck with your rMB!
