x121e Charging threshold on linux

[Shancial]

I bought the Lenovo x121e last fall and have been using windows 7 on it. Since I don't use this laptop for gaming, I would like to put linux on it, but the only problem is that the tp_smapi module doesn't support x121e (yet?) and I haven't found any solution for putting a charging threshold to the battery on Linux. I am thinking of installing Lubuntu or Linux Mint (rolling debian release)

I mostly use the laptop plugged in, but I don't want my battery to degrade. I have seen the damage that constant charging can do to a battery. Currently I am keeping my battery at 50% when on AC.

I am reasonably adept on computer stuff, but on linux specific things I should be considered as an experienced newbie.

Thank you in advance, I appreciate the help!

-Shan

[tarverator]

*bump*

In my case, I have been using Linux Mint Maya on an X230 ThinkPad. I got the machine last fall and used it more or less normally for six months. The battery capacity dropped to 44% and Lenovo is replacing it under warranty. I need a way to control the charging threshold so I don't trash the replacement battery the same way.

[Cigarguy]

Unfortunately there's nothing as easy as Power Manager for Linux as there is for Windows.

I used to be a power Linux user when I was in University (Comp Sci Degree) but have since degress to being a dinosaur. I manage to find this tutorial which allowed me to change the charging threshold on a T400 running Linux Mint 14.

http://www.thinkwiki.org/wiki/Tp_smapi

[tarverator]

I don't think tp_smapi is supported in certain recent model ThinkPads, such as the OP's X121e and my X230. Hopefully I am mistaken. If not, is there any other way to set the charging threshold?

[dr_st]

I need a way to control the charging threshold so I don't trash the replacement battery the same way.

Regardless if the actual topic, I think you will find there is very little correlation between charging thresholds and the longevity of your battery.

[tarverator]

...I think you will find there is very little correlation between charging thresholds and the longevity of your battery.

I am curious about your statement.

I have read in many places, such as officially http://forums.lenovo.com/t5/Welcome-FAQ ... a-p/244800 and in commentary http://blogs.computerworld.com/20269/ma ... er_battery, that keeping a lithium ion battery fully charged shortens its service life. In my own experience, I used my ThinkPad X230 plugged in and/or plugged in overnight thinking that the firmware would prevent "overcharging" and within six months the capacity had fallen to 44% and Lenovo is replacing the battery under warranty. Something doesn't add up.

If I were using Windows, I would simply set the Power Manager (or whatever it's called) to prevent charging past 80% or 90% or so. Using Linux, it isn't clear where or how to set the same thing, as the API that was usually used for this doesn't seem to work on some recent hardware such as mine.

[tarverator]

This http://blog.thekondor.net/2012/09/make- ... holds.html looks good, but it's a bit technical even for me, and I can't figure out how to implement it.

[dr_st]

In my own experience, I used my ThinkPad X230 plugged in and/or plugged in overnight thinking that the firmware would prevent "overcharging" and within six months the capacity had fallen to 44% and Lenovo is replacing the battery under warranty. Something doesn't add up.

And I have my own experience with multiple batteries, which I always left plugged in charged to 96% or 100%. Some of them experienced noticeable capacity loss. Most didn't. Battery brand had a lot more to do with their longevity than any usage habits of mine.

[tarverator]

Some of them experienced noticeable capacity loss. Most didn't. Battery brand had a lot more to do with their longevity than any usage habits of mine.

Good to know, thanks. That I am using a Lenovo battery, and that they explicitly recommend not charging it fully to maximize longevity, and that failing to heed this suggestion (of which I was unaware) has led to unacceptable degradation -- with which they agree, and are replacing under warranty -- suggests to me that in this case I had better play along, except that it is not obvious how to do so under Linux. Maybe there is a huge longevity difference between even a 95% and a 100% typical charge, in some batteries? I wonder how much has to do with chemistry, and how much has to do with management as implemented in firmware? Oh well, I have yet to meet the complex piece of equipment that doesn't have quirks. On this laptop I have discovered that if I close the lid and then yank the power cable before the sleep sets in, it sometimes fails to sleep. So, I have learned to pull the power either before or some time after I close the lid. Manually managing battery charge is a bigger PITA, but not impossible. I would prefer to set what I want in software, obviously, but that isn't always possible.