[ltp] Power drainage on T21

Eric Jorgensen linux-thinkpad@www.bm-soft.com
Tue, 25 Jun 2002 11:12:34 -0600


On Tue, 25 Jun 2002 12:24:05 +0200 (MEST)
ZeiMoT <zeimot@astrakan.hig.se> wrote:

> On 25 Jun 2002, Andrew McMillan wrote:
> > Not sure abou that.  I only ever boot when I am on AC power to try and
> > limit the side-effects of speed changing (last booted on 23rd May) and I
> 
> What are the sideeffects of speed changing ?
> 
> On my R30 I get 1.5hrs of time when it's running with the most powersaving
> options set, and no harddrive reads, all I did was to write some documents
> in emacs (no save during the testing time). All seems to work well the
> first hour and 20 minutes, the battery led was green. apm reported that
> there was 44% left in the battery. Then, almost like someone chopped the
> head of my battery, it dropped to 4% and broadcasted that it now was time
> to save my work... So I did, and the battery led changed from green to
> orange at 1hr 28 minutes. For fun I manually shut down my computer so I
> got everything unmounted correctly without shutting down with the apm, and
> waited. at 1hr 33 minutes the led began to flash in orange an half a
> minute later the battery was completely drained.
> This battery is new and the specifications tell me it is supposed to last
> for 2 hrs. Is that 2hrs without any hardrive access and with maximum power
> savings ? Well, either case it does not last for 2hrs.
> Do you get the same feeling as I get? That the battery is not feeling
> well, a mistake maybe in the making process?


	That really sounds to me like a damaged battery pack. 

	I used to have a Toshiba notebook, and the battery it initially came with,
initially would last me about 3 hours. After a year or so, it would take about
1.5 hours to drain to 50% or so, and then it would drop to 5% after about 5 more
minutes. I bought another battery, which didn't do this. My guess is, some of
the cells in the old pack are damaged, or just worn out, since these are lithium
cells we're talking about I figure damage is more likely. (NiMH cells, in the
bad old days, that would just be from age) 

	Maybe your battery is defective? damaged in shipping? I guess you'd have to
diagnose the same problem in windows before you could satisfy IBM support to the
extent that they'd replace it under warranty, possibly. 

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