# [WORKAROUND] Battery Drains while Off

## larophel

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".

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.

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.Last edited by larophel on Fri Nov 16, 2012 2:07 pm; edited 1 time in total

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## larophel

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

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

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## larophel

Another thing I tried: disabling the LAN driver completely in the kernel. 

Didn't help either, unfortunately.

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## toralf

Bluetooth and wake-on-lan disabled (ethtool -s eth0 wol d) ?

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## larophel

I have tried to disable wake-on-lan just before shutdown, using "ethtool -s eth0 wol d", but it didn't help. 

Wake-on-lan is already disabled in the laptop's BIOS, but "ethtool" always shows it as on after a restart.

To disable bluetooth, I tried the following: "echo 1 > /sys/devices/LNXSYSTM:00/device:00/TOS6208:00/rfkill/rfkill1/state"

Is there another way I could try?

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## larophel

I booted yesterday from an Ubuntu live-CD and shutdown my computer from there.

No battery drainage overnight.

Any idea what might be different between Gentoo and Ubuntu, which could cause this problem?

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## larophel

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. 

Does anybody have any idea what else could cause this issue?

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## larophel

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.

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## nlsa8z6zoz7lyih3ap

Thanks. This solves the same problem for me.

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## gr650

I experienced the same problem with a Toshiba Satellite Z830: battery drains after shutdown at a rate of 25 percentage points per day, so that it was empty after around four days. The hwclock setting didn't change anything for me.

However, what did solve the problem was to disable the "USB sleep and charge" function in my laptop's BIOS. The thing's got one USB port that is permanently supplying power for USB devices even when the laptop's off. Even when there's nothing connected, the port (or that particular hardware function) seems to drain the battery. I disabled the function and there's almost no battery drain (maybe 1% per day) any longer. While you're at it, you may also disable the other Wake-On-X functions (where X is keyboard, LAN, etc.) if you don't need them.

Georg.

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