MBP i7 Battery Unpredictable Readings??

[christophermdia]

Just got a 15" MBP, 8GB Mem, 500GB Momentus XT, Hi Res AG, I love it, this thing flies...So I flew out today on a 3 hour flight, I used it from the minute 10,000 feet hit until they said to shut the comp down....I skyped my wife and kid (i didnt talk but they spoke to me with my headphones on), I surfed the internet the entire time, listened to itunes, I also chatted with my brother and wife for the entire flight as well....at the end of the flight it said 4 hours remaining....however, I also got readings of 2:15, 3:22, and 4:05, sometimes without doing anything but surfling the internet...what are the the variables to trust here? Do I really have 4 hours left or is it more like the 2?

P.S....I do realize that when I skype etc...I will see the battery drop, I am talking only about the times when only safari is open...

 

[alust2013]

Most likely some of those sites had flash in them, which uses more CPU, and gives a lower estimated time for battery. Then it will recalculate when the load decreases, giving a higher reading. It simply calculates roughly how long the battery would last if that exact load were maintained until it died.

 

[ayeying]

The reading is never accurate. The only accuracy is the real time you used it. I wouldn't even look at the time the OS gives.

The OS is trying to predict the very moment of usage, how much power could be left. There's way too much stuff to effect it. If the fans decided to slow down even by 100RPM, it'll affect battery life, etc.