Posted by: Chris Barylick
Date: Thursday, January 7th, 2010, 06:43
Category: MacBook, MacBook Air, MacBook Pro, News
Since installing it, I have to admit that I like Snow Leopard and it has yet to kick my pets or burn my apartment to the very ground.
These are good things.
Even so, per CNET, a large number of MacBook and MacBook Pro owners have noticed a problem with the computer frequently displaying a “Service Battery” warning in the battery system menu. This also seems to be coupled with relatively short battery life, either with the battery discharging rapidly or with the computer going to sleep but still reporting high percentage of charge left in the battery. As of the Mac OS 10.6.2 update, affected users are still experiencing the problem.
This problem appears to be an issue with Snow Leopard’s handling of the battery hardware, where the services that are supposed to detect battery problems are incorrectly reporting the battery status, and subsequently triggering the system to go into a precautionary sleep mode or claiming the battery is draining. This theory is backed up by the fact that affected people who have downgraded back to Leopard either by reinstalling, restoring from backup, or even booting off the 10.5 Leopard DVD have not had the problem occur on the same hardware.
A recent TUAW article suggests this behavior stems from Snow Leopard being fine-tuned to reveal existing battery problems that Leopard was not aware of. While this may be the case for some people, the sheer number of people reporting the problem indicates there may be errors in the software. Unfortunately, there is no easy way to discern those with pre-existing battery problems from those with healthy batteries.
In order to address the issue, the article offers the following tips to help sort things out via the mighty Apple Knowledge Base:
– Calibrating the battery
– Resetting the PRAM
– Resetting the SMC
Strangely, the battery issues have cleared for a few users who have just shut down and restarted their systems on a regular basis. While keeping the power supply plugged in to prevent any issued with the battery, they’ve turned off the machine and rebooted to see the battery being normally recognized. This suggests the problem may be with a setting more than a specific bug, that hopefully can be reset by a full restart. MacBook owners may tend to sleep their systems instead of restarting them, which will keep various settings from being refreshed.
Further supporting the claim of software issues in Snow Leopard is that some users have cleared the problem by booting into 64-bit mode. If you do not have any software that requires a 32-bit kernel and system extensions, try booting into 64-bit mode by restarting and holding down the “6” and “4” keys simultaneously. For some the problem has returned when booted back into 32-bit mode, but for others the switch to 64-bit mode has fixed it even when booted into 32-bit mode.
Another suggestion to address this problem is to remove the power management system preferences, which contains parameters that determine how the system will behave when running on either AC power, battery, or a UPS. This file is called “com.apple.PowerManagement.plist” and is located in the /Macintosh HD/Library/Preferences/SystemConfiguration/ folder, and can be removed without harming anything. This isn’t a fix, however, and those who have done this have found it only seems to temporarily remove the warning in the battery system menu, and does not address the underlying issue.
Lastly, the issue may lie with the upgrade process itself, where settings for Leopard are not working with Snow Leopard. The temporary successes with removal of the Power Management property list suggests this may be a possibility. As a result, try booting off a clean OS installation of Snow Leopard to test the hardware.
If you’ve seen this issue on your end of have found a fix or workaround of your own, please let us know.