[ltp] Has my battery failed?

Tony Willoughby linux-thinkpad@linux-thinkpad.org
03 Jan 2003 15:55:40 -0500

On Wed, 2002-11-27 at 13:06, James Holden wrote:
> Tony Willoughby wrote:
> >My 390E has stopped detecting/using the battery.  
> >
> >My typical practice when leaving work for the day is to run "shutdown"
> >and then pull the power cord to to pack it up.  The system continues to
> >shutdown on battery power.
> >
> >One day last week I did this and the system powered off immediately. 
> >Since then it will not power up unless connected to the AC.  "apm"
> >reports: "AC on-line", it used to report the % charge of the battery. 
> >Reseating the battery hasn't helped.  
> >
> >apm reports the following when started..
> >
> >Nov 26 09:06:39 localhost apmd: apmd startup succeeded
> >Nov 26 09:06:39 localhost apmd[1845]: Version 3.0.2 (APM BIOS 1.2, Linux
> >driver 1.16)
> >Nov 26 09:06:40 localhost apmd[1845]: Charge: * * * (-1% unknown)
> >
> >I always assumed that battery failures would be gradual, not sudden like
> >this.  Has my battery failed or is something else wrong?
> >
> >  
> >
> Quite likely.
> It is often the case that when a Li-Ion battery fails, the electrolyte 
> degrades almost instantaneously. It's a kind of avalanche effect and the 
> actual failure takes only a few milliseconds. At this point, the battery 
> goes short-circuit. It's common for the laptop to crash at this point as 
> the now shorted battery crowbars the power rails via the DC-DC converter 
> before the current limiting kicks in. People often report that the 
> machine crashes, and they won't boot up until they get some mains power 
> into it. This is probably what has happenned. the apm utility is 
> reporting -1% because the microprocessor in the batter which reports the 
> power level is non-functional.
> James

Well, I just bought a new battery and everything is well.
Thanks for the info.

Tony Willoughby     tonyw@pobox.com

"Enjoy every sandwich..."
  - Warren Zevon 30-October-2002