Macbook - Unplug AC power and Mac enters sleep mode

Question

Macbook - Unplug AC power and Mac enters sleep mode

I am using a Macbook with a Dell 24 inch monitor, external keyboard and mouse. The lid is usually closed and I am familiar with the best practices how to use sleep mode.

I have now found that, in the above scenario, unplugging the power cord puts the Mac to sleep immediately. The batter is charged at 99% or better.

The reason why I want to unplug: let it drain to condition the battery according to Apple recommendations.

I am aware of the workaround: disconnect external peripherals, let Mac run on battery until it is drained (I like to think that the peripherals perhaps are part of the issue here).

I was simply wondering if putting the Mac to sleep when AC power is disconnected is a feature, or if anyone here has a suggestion. This has not previously happened to me when I used the Mac without the monitor/keyboard.

Thanks!

Macbook, Mac OS X (10.5.4)

Posted on Sep 14, 2008 2:19 PM

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Answer 1

Sep 14, 2008 3:19 PM in response to Oliver Schneidemann

It requires the power adapter when using an external display. The electronics to drive a DVI port uses some power, and they assume power must be available if you have some place to plug in the external display, so they don't allow it to run an external display on battery only. To drain the battery, disconnect the external display, and run it at full brightness with the llid open and Energy Saving system preference set to never sleep the drive, display, or computer, and to run for maximum speed. You only have to calibrate a battery once. NiCads needed conditioning. Lithium-ion don't. Under some conditions you might extend the life slightly, but full discharges reduce life, so getting it just right is unlikely.

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Answer 2

Sep 14, 2008 3:38 PM in response to Malcolm Rayfield

Thanks, this has been helpful. I looked up First Magnus reply to a posting, and that had an added benefit for me. Thanks!

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