Wireless keyboard and mouse battery meter showing incorrect reading

Question

Level 1

9 points

Wireless keyboard and mouse battery meter showing incorrect reading

Hi,

I've searched the forums and other sites and have not found an answer to this issue.

I have a 20" iMac and use both an Apple bluetooth wireless keyboard and a Magic Mouse. until now, the battery life indicator/meter (accessed by clicking on the Bluetooth icon in the menu bar) has always seemed to be reliable. However, I've noticed over the last few days that it seems to be "stuck". When I start up the machine each morning, I get a low battery warning for the keyboard. The meter indicates the keyboard batteries are at 34%. Firstly, this is too high a reading to generate a low battery warning, and secondly, it's been showing 34% for at least three days now, despite near-constant usage during that time. Similarly, the mouse battery meter shows 85%, and has done for the last few days.

So it seems that the meters are displaying an incorrect battery usage level. Has anyone else come across this, and is there anything I can do to reset/recalibrate it?

I'm running OS X 10.6.6 and using standard alkaline (non-rechargeable) "Energiser" batteries. This the same brand of batteries I've been using for months.

Thanks in advance,

Rob

iMac 20" 2.4GHz 4GB, Mac OS X (10.6.6), ATV 40GB v2.3.1

Posted on Feb 9, 2011 1:24 AM

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Answer 1

Feb 9, 2011 3:04 AM in response to robgrayson

Hello rob:

the battery life indicator/meter (accessed by clicking on the Bluetooth icon in the menu bar)

That is interesting as I do not have that option….. I get battery life from either system preferences or a nice little dashboard widget (mighty monitor).

In any event and FWIW, my indicators are approximately correct.

I do not know where OS X obtains the battery information, but you might try a couple of things:

1. Trash the preference file (com.apple.bluetooth.plist) and restart.
2. Reset PRAM and the SMC (instructions are in knowledge base articles).

Barry

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Answer 2

robgrayson Author

Level 1

9 points

Feb 10, 2011 12:20 AM in response to Barry Hemphill

Hi Barry,

Thanks for replying. I trashed the preference file and restarted, and now the keyboard battery shows 21% and the mouse 82%. This looks more hopeful.

By the way, to get access to bluetooth info in the menu bar, there is a "Show bluetooth status in the menu bar" checkbox in the bluetooth preference pane.

Thanks again for your help,

Rob

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Answer 3

Feb 10, 2011 2:37 AM in response to robgrayson

HiRob:

You are welcome. Looks like the problem may be solved (hopefully).

I have the BT icon in the menu bar. What I did not understand was that I thought clicking on the icon somehow, for you, displayed the battery value directly (rather than going to system preferences).

If you look at it frequently, you might like the Dashboard widget called mighty monitor:

http://www.apple.com/downloads/dashboard/status/mightymonitor.html

Barry

P.S. Your profile entry seems to have slid back to OS X 10.6.3 🙂

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Answer 4

robgrayson Author

Level 1

9 points

Feb 10, 2011 2:53 AM in response to Barry Hemphill

Barry Hemphill wrote:

I have the BT icon in the menu bar. What I did not understand was that I thought clicking on the icon somehow, for you, displayed the battery value directly (rather than going to system preferences).

If you click on the BT icon in the menu bar and then hover over the device name (keyboard/mouse), the battery % is displayed.

P.S. Your profile entry seems to have slid back to OS X 10.6.3 🙂

Oops, not sure how that happened – now corrected – thanks!

Rob

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Answer 5

Feb 10, 2011 2:57 AM in response to robgrayson

Hi again:

If you click on the BT icon in the menu bar and then hover over the device name (keyboard/mouse), the battery % is displayed.

I will be (censored)! Who says +"older dogs"+ (I am one) cannot learn new tricks! Thanks.

Barry

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Answer 6

Feb 21, 2011 2:46 PM in response to robgrayson

I have this kind of problem too and I'm really confuse why there's a constant incorrect reading on my mouse battery.Upon reading those suggestions and I have tried to resolve it just following the guidelines been post in this thread, I have resolved the issue on it. Thank you guys.

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Answer 7

Mar 21, 2011 5:18 PM in response to Barry Hemphill

I have this issue too!
The steps doesn't work for me.
iStat Menus and Mighty Monitor both shows the same percentages, but the built-in Bluetooth menu shows the incorrect percentage.
I check the com.apple.bluetooth.plist file; the percentages in the file is the same as the readings on the iStat Menus and Mighty Monitor. I thought something is wrong with my OS, so I reinstall it. BUT, no luck.

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Answer 8

Apr 6, 2011 6:27 PM in response to AndrewLih

I'm also having issues with the bluetooth keyboard.

One minute it says 100%, the next 17%...then 75% then 100%..very weird.

I also get a message saying that the batteries are low when it says 100%.

Could this be a fault with the keyboard??

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Answer 9

Aug 9, 2011 4:34 PM in response to robgrayson

Having the same bug but I am on 10.7 apple bluetooth menu says 100% but istat menus battery icon say 98% now used to say 89% about an hour ago

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Answer 10

Dec 14, 2011 5:07 AM in response to Barry Hemphill

Barry, Could you post the path to com.apple.bluetooth.plist? Assuming that does the trick, I'll try to remember to have robgrayson indicate that your provided the correct answer. Thanks!

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