MBP battery drains in Boot Camp

klukk · #1 January 14th, 2009, 02:53 AM

The power adapter is plugged in and the battery switches from charging and "on AC power". It results in the battery slowly being drained and the MBP shuts down after a few hours. I dont have this problem while in Leopard. I have tried using two different power adapters with no luck.

Thanks

2,4 GHz CPU Intel Core 2 Duo
2GB RAM
Nvidia GeForce 8600GT
15,4" glossy
Windows XP

Satcomer · #2 January 14th, 2009, 04:33 AM

Windows XP does NOT recognize the the MacBook is a portable and is running full bore in Boot Camp (when on the battery). One has to go into the windows Control Panel panes and find the settings to sleep the hard disk, dim the screen after a certain time when on battery.

klukk · #3 January 14th, 2009, 07:04 AM

Im not sure if I understand what you are saying, but I cant see why the battery power is decreasing while the power adapter is plugged in. I have tried physically removing the battery but it shuts off almost instantly when I try to play games. Maybe it has something to do with the graphics driver? I have the latest NVIDIA drivers for laptops, but Im not sure if they are supported by Apple.

ElDiabloConCaca · #4 January 14th, 2009, 01:59 PM

All the drivers you need (and should install) for Windows running under Boot Camp are included on the Leopard DVD. You should not install any drivers other than those included on the Leopard DVD. Perhaps this could be causing the problem?

klukk · #5 January 15th, 2009, 02:40 AM

installed all the boot camp drivers and upgraded to 2.1 but it didnt work

AkleyMac · #6 February 1st, 2009, 02:46 PM

This is very strange... The computer should not be using the battery at all when running on AC power. I've run Vista on mine no problem without a battery in it, although mine is the 2.16GHz with ATI graphics.

I'm not all that familiar with the advanced settings in Windows, but I can't imagine there would be anything to explain this. The best thing I can think of is to restore the drive to a single partition with BootCamp (or Disk Utility) and reinstall XP.

klukk · #7 February 2nd, 2009, 09:49 AM

I have reinstalled Boot Camp and Windows XP but it still is not working. Do you think the problem will be solved if I purchase a new battery? My current one is getting old and only lasts about one and a half hours before it is empty.

AkleyMac · #8 February 3rd, 2009, 07:57 AM

Ok, I've just done some reading.

It looks like this is normal behaviour - under very heavy CPU load, the system draws power from both the AC and battery:

http://support.apple.com/kb/HT2332

I am guessing you wouldn't notice this in Mac because the system will reduce the CPU speed to stop it from shutting down on low battery.

In response to your last question, this would mean that buying a new batter should increase the amount of time you can game for, but not resolve the issue altogether.

I'm surprised the BootCamp drivers don't handle this, but it looks like it's normal. Someone else is experienceing the same here:

http://discussions.apple.com/thread....sageID=8328115

Sorry I can't be of more help - I've never experienced this, but maybe I don't play intensive enough games...