Battery Drains while Off (ACPI-related)
 

I got a new laptop a while ago, and have been having the issue that the battery drains while the laptop is off.
By "off", I mean a full shutdown (e.g. shutdown -h now).
Over an eight hour off-period, the battery discharges around 15-20%.

This seems to be a Linux / ACPI-specific issue, because it does not happen if I shutdown the laptop from Windows.
It also does not happen if I boot Linux with the "acpi=off" kernel parameter, and then perform a shutdown.
I have tried various things to solve this, but have been unsuccessful:

1. Replace the battery.
2. Upgrade from kernel 3.2.12 gentoo sources to 3.4.9 vanilla sources.
3. Disable all power / wakeup related features in the laptop's BIOS.
4. Disable wake-on-lan using the command "ethtool -s eth0 wol d". Even though wake-on-lan has been disabled in the BIOS, "ethtool" shows it as on after every reboot.
5. Disable all wake-up actions in /proc/acpi/wakeup.
6. Disable bluetooth using "echo 1 > /sys/devices/LNXSYSTM:00/device:00/TOS6208:00/rfkill/rfkill1/state".
7. Disable the wlan adapter using the FN+F8 hotkey.

Here's my kernel .config: http://pastebin.com/NRzK85bp
Here's my dmesg output: http://pastebin.com/BW4fE4tG

I can't think of anything else to try, but I also want to avoid using the "acpi=off" parameter, because then various programs don't work.
I would appreciate any help / hints.

Yesterday, I downloaded an Ubuntu live-CD and shutdown my computer from there.
No battery discharge overnight, so I am even more convinced that this is a wrong setting / wrong driver on my system.
I just don't know which one...

Does your laptop really power off?
I have a Dell D630 with Debian on it and sometimes when i issue a shutdown, the system doesnt really stops (hdd powers off and all, but the fan sometimes remains on, th epower led too). It does stop if i press the power button for a few seconds.

The (power) leds do go off.
I am not sure about the fan, I will check it.

Go through the power off settings.

Hibernate should lie idle and consume no power, although anything in usb sockets may consume power.
Suspend does use a little power and the usb comment also applies
If you have it set to 'wake on' something, it has to monitor that, obviously. That's a bios setting usually, so disable wake on anything.

Also see http://www.lesswatts.org

My eeepc's and Acer Aspire One does what businesskid is suggesting to look at. They drain power from the battery to like plug in a phone charger to usb. It is considered a feature.

These netbooks may be older than your laptop though. I just pull the battery after shutdown when put those netbooks away for the day.

Edit: I don't know enough about acpi kernel configs or Gentoo to help though on what to edit in kernel config in Gentoo to kill usb power after shutdown.

> Go through the power off settings.

Could you provide some more details? Which power off settings?

> Hibernate should lie idle and consume no power, although anything in usb sockets may consume power.
> Suspend does use a little power and the usb comment also applies

I am not suspending nor hibernating my computer, I am shutting it down (shutdown -h now).

> If you have it set to 'wake on' something, it has to monitor that, obviously. That's a bios setting usually, so disable wake on anything.

See points 3. and 4. of my OP.

The issue does not seem to be kernel-related, after all.
I installed Ubuntu on a different disk, and compiled the 3.4.9 kernel there, using the same kernel config as on Gentoo.
The battery still does not discharge over night when shut down from Ubuntu.

Does anybody have any idea what else could cause this issue?
Are there any Ubuntu-specific ACPI configs somewhere?

Hi there,

It seems the "battery draining while off" problem is quite common among Linux laptop users.

I have it on my HP Pavilion DM1 3130 (running Arch), now I need to try with Ubuntu to see if it does the same!

Thanks for the info, maybe we will discover the cause of this bug...

In the meantime, I have gathered some more information.
As I did not manage to reproduce the issue in Ubuntu, I started suspecting some software being the culprit.

So, I started Gentoo and used the "interactive startup" feature to stop all init scripts from running.
When I did not allow any of the init scripts to start, my battery did not drain over night!

To pin-point the cause, I have been repeating that process, but allowing one init script every night.
Thus, I have noticed that most likely the "udev" init script and / or software is to blame for the battery drain.
Tonight, I will run one last test, by enabling the "udev" init script.
If tonight my battery drains, then that should be the proof that "udev" causes the battery drain.

Of course, that will still not explain why the battery drains, but at least I will be one step closer to solving this problem :)

I finally found the cause of the issue: the command "hwclock --systohc --local" causes the battery to drain when the laptop is off.
This command is executed by the /etc/init.d/hwclock script.
If I set clock_hctosys="NO" in /etc/conf.d/hwclock, that command does not get executed anymore, and the battery does not drain.