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battery discharge order changed by now?

Posted: Tue Nov 30, 2010 3:45 pm
by tom121
I once saw a thread discussing the battery discharge sequence, when both the regular and the ultrabay battery are plugged in. Previously, the ultrabay battery gets drained first, then the main battery, which does not make sense, or there is poor (no) reasoning behind that. A reason to switch the order is: after the main battery is drained, the juice in the small ultrabay battery allows one to remove the main battery and plug in a full main battery without having to restart the computer.
Is this fixed by now?

thanks
T

Re: battery discharge order changed by now?

Posted: Tue Nov 30, 2010 5:23 pm
by frankiepankie
I thought you can switch the main battery even without having a Ultrabay battery.

On my FrankenPad (T40 with R51 mainboard) i can do it with the "Remove and replace battery" in the Battery MaxiMiser menu.

I believe it hibernates and then you can change the battery.

Re: battery discharge order changed by now?

Posted: Wed Dec 01, 2010 3:38 pm
by SHoTTa35
You can always hibernate and/or shutdown to replace batteries. The UltraBay battery could fix that problem by still powering the system even after the main battery has been pulled out to swap. This is good in cases where you are downloading something or doing some running work and you just can't shut down now to do that.

To answer the OP, no that's still "by design" :roll:

Re: battery discharge order changed by now?

Posted: Wed Dec 01, 2010 6:52 pm
by richk
Power manager 3.31 was released this week. The description says it fixes this issue. It is not showing up in "system update" yet, but you can install it.

Re: battery discharge order changed by now?

Posted: Fri Dec 03, 2010 10:13 pm
by tom121
I expected more like a solution implemented in the BIOS. I am running linux, and so don't have the power manager 3.31 you are referring to.

Re: battery discharge order changed by now?

Posted: Wed Dec 08, 2010 1:46 am
by gdi2k
On Linux I believe this is possible using tp-smapi, see:
http://www.thinkwiki.org/wiki/How_to_us ... _batteries

I would be interested to hear if you can get this to work - I only have an X200 so can't test, but am eying a T410s (or more likely its successor early next year).

As far as I understand, once you have the tp-smapi module loaded, you should be able to pass the "force_discharge" parameter to your system battery via sysfs to make it discharge instead of the ultrabay battery.

Required steps for recent Ubuntu (you should become root first as you can't modify /sys parameters via sudo for some reason):

Code: Select all

apt-get install tp-smapi-dkms
modprobe tp-smapi
echo "1" > /sys/devices/platform/smapi/BAT0/force_discharge
To force discharge of the Ultrabay battery, it's "BAT1". Note that forcing a discharge on a battery will make it discharge even when connected to AC. To stop forcing a battery to discharge, pass "0" instead of "1" in the above command.

If this works, you could pile the above into a script and launch it from your taskbar when needed.