Author Topic: Incorrect Battery info on a dell Vostro 1520  (Read 10311 times)

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indianajones

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Incorrect Battery info on a dell Vostro 1520
« on: May 04, 2010, 03:06:10 AM »
Hi,

I originally posted this message at insanelymac forum, but nobody responded. I'm hoping I can get help here before I decide to wipe my OSX installation.

I have a Dell Vostro 1520 running 10.6.3 vanilla. All updates have been applied using software update without any issues what so ever. Infact OSX runs so well that I hardly ever boot Vista which lives on a separate partition.
Recently I got a replacement battery from Dell under warranty, the previous battery would only provide me with 30 mins of run time. The new battery brought back the 1:45-2 hrs of run time I originally had with a new laptop. OS X ran fine with the new battery for a couple of weeks and reported a normal charge time, upto 1:45 depending on how discharged the battery was. A couple of days ago, I shutdown the laptop since sleep doesn't work. When I rebooted the machine the next morning, I noticed that the charge time was in excess of 14 hrs! Several reboots later the situation did not change and I began to suspect the new battery. I booted into Vista to check if the same problem existed under windows but Vista correctly reports a charge time of 1:40, so the problem is definitely with my OSX installation. Dell's website lists my 6 cell battery as 2200 mAh but System profiler reports it to be 48840 mAh! I could live with the problem but the low battery alarm keeps popping up everytime I disconnect the adapter. I've been cycling the battery to get a longer life, and its getting really annoying.

I've attached two screen shots showing the screen charge time displayed with the adapter plugged in and just after disconnecting the adapter. SystemProfiler reports VoodooBattery kext version 1.3.2

I'd really appreciate if someone could help me with this or point me in the right direction.


Indiana

« Last Edit: May 04, 2010, 03:27:20 AM by indianajones »

Superhai

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Re: Incorrect Battery info on a dell Vostro 1520
« Reply #1 on: May 04, 2010, 01:49:08 PM »
Download the debug version of the kext and post the output from the the logs related to it.

indianajones

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Re: Incorrect Battery info on a dell Vostro 1520
« Reply #2 on: May 05, 2010, 04:42:54 AM »
Hi,

Attached with this message is an extract of the relevant system messages. I deleted system messages from other components. I am also attaching another interesting screen shot from Vista. I downloaded a program called BatteryMon to get more detailed battery status monitoring under Vista, and upon running it I discovered that I actually had a 48 Wh battery. The battery also has 48 Wh printed on it. For some reason I thought I had a 6 cell 2200 mAh battery, but BatteryMon reports that I actually have the 4000 mAh battery.

More interestingly, I could finally understand what OS X currently reports as 48840 mAh is actually the battery mWh capacity. I have not idea why OS X suddenly decided to report mWh capacity instead of mAh values....
Also I don't know if this is interelated, but I find that I can no longer increase decrease the screen brightness using the keyboard. It also used to work fine until a few days ago....

Please let me know if you need any other data,

Finally thanks for your help, I really appreciate it.

Indiana

indianajones

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Re: Incorrect Battery info on a dell Vostro 1520
« Reply #3 on: May 05, 2010, 04:57:23 AM »
And another log file, taken with 10 minutes remaining on battery charge.
Thanks once again

Indiana


indianajones

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Re: Incorrect Battery info on a dell Vostro 1520
« Reply #4 on: May 05, 2010, 06:08:54 AM »
Well, it appears that the problem has solved itself! I shutdown the laptop, pulled the battery out, disconnected the adapter and pressed the start button during 20 seconds. I then plugged the adapter and booted. I noticed that I had gotten back the abillity to contol screen brightness from the keyboard. It might seem trivial, but the high brightness screen is very hard on my eyes. Anyway I got to the OSX desktop screen and then plugged in the battery.... and to my amazement, the battery charge time was now 0:55. System Profiler is also reporting a full charge capacity of 4495 mAh, which is correct.

Although I am happy to get my "Macbook Pro" back to normal, I would definitely like to understand what happened, so that I can try to avoid the problem in future.

Attached are the latest System Profiler screens and the Voodoo logs. I'd like to keep the debug version of the VoodooBattery kext. Are there any issues apart from the fact that my log files are going to be full of Voodoo logs?

Thanks for your help

Indiana

Superhai

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Re: Incorrect Battery info on a dell Vostro 1520
« Reply #5 on: May 05, 2010, 09:51:25 AM »
Thanks. I found the bug. Because OS X always expect values reported to be in mA and not mW, I ensure the kext convert it. But there is also one other case, which I unfortunately placed after that routine, and it is when your battery reports that it have more capacity than the designed (or factory set max capacity). Because it reads the actual (mW) values again directly from ACPI, and is not calculating the mA values the value is wrong. I have updated the code, so it shouldn't happen again, and will upload a new version now.

The reason for the weird report is often due to poor calibration of the battery, and as it seem like the battery have recalibrated, it was then again working.
« Last Edit: May 05, 2010, 09:57:32 AM by Superhai »

indianajones

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Re: Incorrect Battery info on a dell Vostro 1520
« Reply #6 on: May 06, 2010, 03:59:13 AM »
Updated to version 1.3.3 and my charge time is back 1:20!!
Wooooohooooooooo!!!!
Thanks Superhai, glad I was able to contribute to the development!