View Full Version : 17" unibody MBP battery policy

25th March 2009, 07:16 AM
Shiny new 17" MBP maxed out to the hilt delivered yesterday. Way cool.

Just wondering if anyone knows if it's best to unplug after the battery has fully charged or is it OK to leave it plugged in; ie does that affect battery life in any way. I know with the old G4 PowerBooks it was best to disconnect after fully charged but this new unibody battery and a quick search haven't found the answer on the net or these forums yet.


25th March 2009, 07:33 AM
It's definitely best to unplug it. Having it plugged in all the time can kill the battery fast... The battery isn't totally different to those in other macbooks/older macs... just that it is much bigger.

More battery tips can be found here: Apple - Batteries - Notebooks (http://www.apple.com/batteries/notebooks.html)

25th March 2009, 07:57 PM
isnt there some really fancy circuitry designed for the recharging of the 17'?

28th March 2009, 08:03 AM
The newest technology batteries are designed to be charged fully- and then used as whatever is most convenient. There isn't any reason why you need to charge the battery and then operate from the battery exclusively until it is discharged again. For most people, the most convenient way to use a laptop would be to use it on power when power is available and on battery when it isn't. It's worth keeping in mind that the laptop will use SpeedStep more aggressively to conserve battery life when on battery power. SpeedStep is an Intel technology that adjusts processor performance based on what the demand is - for example, if you have a dual-core 2.66GHz laptop but you're only doing word processing, it may cut the speed to 1.25GHz and operate on one core only, thus saving energy. SpeedStep will become more aggressive at cutting power when the battery becomes lower, or in other extreme circumstances (for example, if the machine is overheating).*When the laptop is operating on mains power, there is basically no need to step the speed down due to power constraints.*