battery-time and cores

[sir. mac]

As I travel extensively battery-life is a big issue for me. So far I´m really pleased with the performance of my 2 week old MBP C2D, which lasts me nearly 4 hours of video (not DVD). I did the battery-calibration and always let it run to empty if I disconnect the power-supply. Anyway, I´ve been trying to monitor the cpu speed with the somewhat unreliable CoreduoTemp, and noticed that it would stay at 2.ghz, even though settings set to "maximum battery life". I don´t know if this reading is correct, but is there a way to throttle down cpu-speed and make it constant at a specific level?

I also read somewhere that you could manually set the number of active cores (in the devtools?). How then do I set it to only one active core, and would this at all impact battery-time?

 

[flalaw]

if you want to maximize your battery life, don't let your battery run to empty every time you use it. your battery has only a set number of charge cycles in its life. so if you run it down lets say 10 percent, then charge it back up, you've only used 1/10th of a charge cycle.

read this for more info:

http://www.apple.com/batteries/

 

[sir. mac]

thanks. I remember reading about this, but forgot it!

But what about the cores?

 

[sir. mac]

This app will supposedly adjust the core-speeds:http://www.xlr8yourmac.com/feedback/coolbook_utility/coolbook_utility_tests.html
Be warned though, read somewhere that some people had problems with stability after install.

Anyone care to explain how you switch off a core in the devtools?

 

[ChickenSwartz]

if you want to maximize your battery life, don't let your battery run to empty every time you use it. your battery has only a set number of charge cycles in its life. so if you run it down lets say 10 percent, then charge it back up, you've only used 1/10th of a charge cycle.

read this for more info:

http://www.apple.com/batteries/

Any idea how many cycles a MBP's battery can take before it starts to diminish, to let's say, 80% of the original life?

 

[sir. mac]

As I´ve lost 1% after 8 cycles I would say 160 before 80%, but that number seems a bit short.

Read somewhere that one should let the battery go down to 40% before charging it, as this would be easier on the cycle numbers. After I read it the guide was removed so I don´t know if this was because it´s just wrong or what. The Apple-pages on battery-care doesn´t mention this though.