T400 battery discharges when the laptop is hybernathed. Why?

[giasoldacastlar]

Hi

I usually hibernate my T400 (2765-D3D) before going to bed. And I did the same in the past with all the laptop I owned (among which a T42). Then I usually unplug it and get it ready for the next day in its bag.
I now noticed that the laptop 6 cell battery discharges slightly overnight (down to 90% but even more if I don't plug in the laptop for longer). This never happened with any other laptop.
As a first solution, I got a new battery as I thought that the first one might have been defective. This was clearly useless as the battery kept discharging.
Then I updated the bios to the very last release and then disabled (in the bios) any feature I thought might keep consuming power: wake on lan for example.
Also this did not make any difference.

Do someone else noticed a similar fact?
Do anyone have an explanation for this behavior?
Which other features would you disable in the bios?

Thanks a lot
R.

[caramerdo]

Check if the ultrabay drive is on while hibernating, and check if wake-on-lan is really disabled - because apparently disabling wake-on-lan in the BIOS does nothing, I have to disable it in software. Also, disabling the expresscard and pccard in the BIOS doesn't really disable them.

[giasoldacastlar]

Thanks Caramerdo,
how do I disable this features in software? I use Windows XP, is it simply from the control panel or I do need a Lenovo utility?
Thanks again

[update: I followed the instructions found at this link:
http://www.microsoft.com/whdc/archive/netpm.mspx. Is this sufficient? Any other suggestion? Thanks!]

[T400plus]

I had a similary query sometime back with my T400 (WXGA +).It turned out that the wake up on Lan feature should be disable if you want hibernate not to wait to be kicked out of slumber.That option was draining 7% of a full charged battery in hibernate mode.


I had leanrned this sometimes in 2003 when the T41 where being over priced and sold.
The disabling in this case is via bios settings.Some Lenovo support (lucky Guys and gays) dont know this stuff so dont expect them to inform you about that

[iamdmc]

Here's a trick: After the system has entered into hibernation (no lights) take out the battery and see if it discharges by itself (it won't more than a percent or so).

What you might be noticing could be due to minor power drain by some devices in your laptop, or it could be that you're unplugging the laptop before you put it into hibernate, and when it comes out of hibernate it's still unplugged (entering and resuming from hibernate requires a lot of power, for some reason)

Cheers

[giorgosvam]

If the above Trick works and you are using Vista, the following will most likely be your solution:
http://support.microsoft.com/kb/970030/en-us

It may also apply to Windows 7, but I would first make a back up before trying it out on W7.

George