Battery "design capacity" incorrect

Battery "design capacity" incorrect

[Matthew Keller]

I've got a *very minor* problem. In fact, it's almost so trivial it's
cosmetic, but if there is an easy fix it would be one less nuisance!

ACPI is working SPLENDIDLY (2.4.21-pre<something> + acpi patches) and
I'm very happy with it. It does, however, think my battery has a "design
capacity" much higher than it actually is. This results in various
scripts I've written, as well as the Gnome battery applet thinking it's
always only 71% full even when it's fully charged and a-ok. It does the
same with my spares of the same make/model. Below is the output
(/proc/acpi/batter/BAT1/info) for the battery in my Gateway Solo 1450X.
The design capacity should be right around what the "last full capacity"
says. I've confirmed this on Sanyo's site. I would like to note that
everything is **perfect** with a different Sanyo model battery that is a
"extra capacity" battery. Is there any source I can diddle? Proc entries
I can echo some magic number into? etc? Thanks!

present:                 yes
design capacity:         5400 mWh
last full capacity:      3864 mWh
battery technology:      rechargeable
design voltage:          11100 mV
design capacity warning: 250 mWh
design capacity low:     100 mWh
capacity granularity 1:  10 mWh
capacity granularity 2:  25 mWh
model number:            UAL3$
serial number:
battery type:            LION
OEM info:                SANYO

-- 
Matthew Keller
Enterprise Systems Analyst
Computing & Technology Services
State University of New York @ Potsdam
Potsdam, NY USA
http://mattwork.potsdam.edu/



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RE: Battery "design capacity" incorrect

[Grover, Andrew]

> From: Matthew Keller [mailto:mgkeller-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] 
> Below is the output
> (/proc/acpi/batter/BAT1/info) for the battery in my Gateway 
> Solo 1450X.
> The design capacity should be right around what the "last 
> full capacity"
> says. I've confirmed this on Sanyo's site. I would like to note that
> everything is **perfect** with a different Sanyo model 
> battery that is a
> "extra capacity" battery. Is there any source I can diddle? 
> Proc entries
> I can echo some magic number into? etc? Thanks!
> 
> present:                 yes
> design capacity:         5400 mWh
> last full capacity:      3864 mWh

So it always returns 5400 mWh, no matter what, is what I think you're
saying, yes?

If this isn't a problem on Windows, I think we can assume it is using
the last full capacity when generating percent full numbers. Maybe we
should do the same?

Regards -- Andy


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RE: Battery "design capacity" incorrect

[Matthew Keller]

On Mon, 2003-03-03 at 12:16, Grover, Andrew wrote:
> > From: Matthew Keller [mailto:mgkeller-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] 
> > Below is the output
> > (/proc/acpi/batter/BAT1/info) for the battery in my Gateway 
> > Solo 1450X.
> > The design capacity should be right around what the "last 
> > full capacity"
> > says. I've confirmed this on Sanyo's site. I would like to note that
> > everything is **perfect** with a different Sanyo model 
> > battery that is a
> > "extra capacity" battery. Is there any source I can diddle? 
> > Proc entries
> > I can echo some magic number into? etc? Thanks!
> > 
> > present:                 yes
> > design capacity:         5400 mWh
> > last full capacity:      3864 mWh
> 
> So it always returns 5400 mWh, no matter what, is what I think you're
> saying, yes?
> 
> If this isn't a problem on Windows, I think we can assume it is using
> the last full capacity when generating percent full numbers. Maybe we
> should do the same?
> 
> Regards -- Andy

Correct. My main question is where is ACPI "getting" the 5400 from?
Various Windows tools, and even the manufacturer's specs claim "3860" or
"3870" as the capacity (tools and manufacturer respectively). I've
changed various Linux tools that I've written to do the math based on
the "last full capacity", but a lot of "other people's tools" use
"design capacity" which is "better", in my opinion as it can let you
know if you're having a calibration problem.

-- 
Matthew Keller
Enterprise Systems Analyst
Computing & Technology Services
State University of New York @ Potsdam
Potsdam, NY USA
http://mattwork.potsdam.edu/



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RE: Battery "design capacity" incorrect

[Grover, Andrew]

> From: Matthew Keller [mailto:mgkeller-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] 
> > > design capacity:         5400 mWh
> > So it always returns 5400 mWh, no matter what, is what I 
> think you're
> > saying, yes?

> Correct. My main question is where is ACPI "getting" the 5400 from?
> Various Windows tools, and even the manufacturer's specs 
> claim "3860" or
> "3870" as the capacity (tools and manufacturer respectively). I've
> changed various Linux tools that I've written to do the math based on
> the "last full capacity", but a lot of "other people's tools" use
> "design capacity" which is "better", in my opinion as it can let you
> know if you're having a calibration problem.

ACPI is getting the 5400 by calling the _BIF control method, which
returns that value - i.e. from the BIOS.

I'd have to see the ASL to know whether the BIOS is dynamically
determining that, or not.

Regards -- Andy


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RE: Battery "design capacity" incorrect

[Troy Schultz]

> Correct. My main question is where is ACPI "getting" the 5400 from?
> Various Windows tools, and even the manufacturer's specs claim "3860" or
> "3870" as the capacity (tools and manufacturer respectively). I've
> changed various Linux tools that I've written to do the math based on
> the "last full capacity", but a lot of "other people's tools" use
> "design capacity" which is "better", in my opinion as it can let you
> know if you're having a calibration problem.

I wonder if the design capacity in your case is the capacity of the
battery if it were fully charged and then fully depleated, a situation
which would and should never occurr.  The last full capacity is what
should be used in any calculation of percent charged as this will be
changed to reflect the battery wear as the battery goes through its
usefull life.

I have made changes to the battstat applet I use to use the last full
capacity in the calcualtions.

Best Regards
-- 
Troy Schultz <tschultz-zzOxFVvAfJPQT0dZR+AlfA@public.gmane.org>



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Re: Battery "design capacity" incorrect

[Richard Black]

I see this patch (design capacity patch) at 
http://sourceforge.net/projects/battstat/; however,
I don't see the 2 battery patch someone had not too long ago.  

Whoever has the 2 battery patch, could you post it to 
http://sourceforge.net/projects/battstat/?

Thanks in advance,
Richard Black

Troy Schultz wrote:

>>Correct. My main question is where is ACPI "getting" the 5400 from?
>>Various Windows tools, and even the manufacturer's specs claim "3860" or
>>"3870" as the capacity (tools and manufacturer respectively). I've
>>changed various Linux tools that I've written to do the math based on
>>the "last full capacity", but a lot of "other people's tools" use
>>"design capacity" which is "better", in my opinion as it can let you
>>know if you're having a calibration problem.
>>    
>>
>
>I wonder if the design capacity in your case is the capacity of the
>battery if it were fully charged and then fully depleated, a situation
>which would and should never occurr.  The last full capacity is what
>should be used in any calculation of percent charged as this will be
>changed to reflect the battery wear as the battery goes through its
>usefull life.
>
>I have made changes to the battstat applet I use to use the last full
>capacity in the calcualtions.
>
>Best Regards
>  
>

-- 
Sincerely,
Richard Black
http://www.cpqlinux.com
http://www.compaq.com/linux





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