Notebook Users Report Battery Errors Under Snow Leopard, Workarounds/Fixes Suggested

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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 “” 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.

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4 Responses to “Notebook Users Report Battery Errors Under Snow Leopard, Workarounds/Fixes Suggested”

  1. I thought my battery was just on the way out, but perhaps its just snow leopard. My laptop is displaying all the symptoms. The worst being when it shuts down with no warning showing an hour of battery life remaining. very irritating!

  2. I had this exact problem. Took the laptop to the Genius bar who recommended a new battery! Wonder if I’ll get a refund now, given the battery was only 18months old and had less than 300 cycles

  3. This just started happening this past week for me, my 2007 core 2 duo macbook pro shutting down automatically with battery showing 40% charge and displaying a service battery message. I took it to the Apple store here in Beijing and they diagnosed a bad battery once they ran their own diagnostic software on my computer and are replacing the battery which was just under a year old. This leads me to believe it was this issue in the article and not a bad battery.

  4. I’ve been following this issue since its genesis (and copped a fair hammering from a few noisy characters in the Apple Discussion thread that seems to have formed the basis of the CNET article mentioned above as a result!) 😉 Contrary to some of the suggestions on the AD boards I am neither an Apple Employee, nor an “Apple Right or Wrong” loverboy. I do, however, think that the manner in which this matter has been covered in some places has produced a lot more confusion than clarity.

    Firstly, it needs to be pointed out that almost everyone experiencing these issues is running an older computer. 2006 and 2007 MacBooks and MacBook Pros dominate the discussions to the exclusion of all else. The batteries in most of these computers are 2 to 3 years old. The average effective life expectancy of a Lithium Polymer battery of that era is just that – two to three years. Millions of these computers were sold during that period. Millions of the batteries fitted to them are right in the heart of the “danger zone” and thousands of them will being dying just about very day at present regardless of what OS they are running under. This problem may well also be compounded by the “recall” issue of 10 million Sony batteries during the first year or two of the MBP arriving on the scene because of fire issues. It is hard to imagine that Sony were over generous in maximising the “oomph” of the batteries that they had to replace as a result and more than a few premature failures could probably be predicted consequentially.

    Similarly , literally millions of MBP and MB users have updated to Snow Leopard over the last few months. The only Macs that can run SL have Intel processors, 75% of Mac sales in the “Intel” era have been to MB and MBP owners, and over 5 million copies of SL have already been sold. If you combine this with the figures mentioned above for ageing MBP batteries you don’t have to be a statistician (though have I have some basic post grad experience in the statistical area myself) to realise that a heck of a lot of batteries are going to die in 2006 and 2007 model MBPs soon after installing SL as a consequence. People being what they are, when two events occur in close proximity, it is all too easy to put two and two together and make five, regardless of the real causality!

    But clearly this isn’t simply a matter of probability. It is just the “backdrop” to the situation, though it probably plays a part in many of the complaints.

    There do seem to be at least some situations where Snow Leopard DOES pull more power than Leopard did (though there may equally be situations where the reverse is true). The best documented example involves accessing “Flash” sites under Safari in the default 64 bit mode in Snow Leopard. Flash has always been a processor hog, but the SL version seems to have taken this to new levels. Have a look at The author of the anandtech piece blames the awful Flash performance on Snow Leopard but surely the same questions need to be asked of Adobe, the makers of “Flash” these days , who aren’t exactly renowned for keeping up to date with Mac OS’s!

    Directly contrary to some of the advice appearing in various places, rather than booting in 64 bit mode, simply running Safari in 32 bit mode seems to make quite a difference here, though I suspect Apple and Adobe will have to work together for a proper resolution of the matter!

    The next part of the puzzle involves the nature of warnings offered. From what I can gather the “old” (Leopard) warnings were simply based on the maximum current capacity of the battery and its maximum voltage. The new (Snow Leopard) “service battery” warning seems to be based on the ability of the battery to actually meet power demands rather than simply voltage levels. If demand is high enough and the battery’s response is close enough to the edge to be in trouble meeting it, then the “Service Battery” warning appears. Pretty clearly people whose old batteries had been trundling along with sufficient voltage maintained without being put under real stress were going to get a shock when they saw it. So, a lot of people were going to see a warning that hadn’t confronted them before, and inevitably were a tad put out by the experience. In the past many people used to complain when their MBPs shut down without warning. These days some complain that they get a “service battery” message and then their MBPs shut down “without warning”. Not quite sure what they imagine the “service battery” message was all about in such cases! 😉