[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: power management problems

I realize this is getting old but...  I am just now getting back to it.

Ritesh Raj Sarraf wrote:
> rrs@learner:~$ cat /proc/acpi/battery/BAT0/state
> present:                 yes
> capacity state:          ok
> charging state:          charging
> present rate:            619 mA

What is your state when running on battery?  The above shows it
charging at 619mA.  But the discharge rate would be interesting in
projecting how much battery life *should* be available.  For example
my T42 (with my bad battery) shows:

  charging state:          discharging
  present rate:            16033 mW
  design capacity:         47520 mWh
  last full capacity:      23300 mWh

This battery has only half of the design charge available.  (It is
basically shot.  I use it whenever I am going to have the laptop
plugged in for long periods of time.)  23300 mWh / 16033 mW = ~1.45 h
For me this is a fairly accurate prediction of battery life.

> remaining capacity:      286 mAh
> present voltage:         12590 mV
> ...
> design capacity:         4800 mAh
> last full capacity:      1003 mAh

With a last full capacity of 1003 mAh and a similar discharge rate as
my T42 of 1335 mA would yield around 0.75 hours or 45 minutes of
projected battery life.  Your report of 10 minutes would mean
1003 mAh / 0.66 h = 6020 mA or just around 6 Amps!  Wow.  My laptop
burns 1.3 Amps.  That is a huge difference and one that I find hard to
believe that a laptop could drain at the rate of 6 A.

This information should also be available under other operating
systems.  I think looking at the discharge rate in the different
systems would be a good indication of how well things are working
between the two of them.

For my T42 the MS discharge rate is lower at 1.17 A than the Linux
discharge rate at 1.33 A and I have not been able to completely reduce
that gap.  Display brightness is a large power lever.  I can also save
some additional power by disabling unused components when they are not
used such as the dvdrom, usb, and wifi but as far as I can tell the MS
system does not disable those components and so I have not been able
to reconcile the differences.  Fortunately for me it is not a large
difference.  But I would like to close the gap just the same.

> If possible, Please CC me when replying. I'm not subscribed to the list.

Sorry, I missed this request in my previous response.


Attachment: signature.asc
Description: Digital signature

Reply to: