Re: [Slightly OT] Laptop battery draining in Lenny

[Gilbert Sullivan <whirlygig@comcast.net>]

On 07/30/2010 08:08 PM, Christian Jaeger wrote:
> 2010/7/30 Mark<mamarcac@gmail.com>:
> > Or do you shutdown  when the battery
> > reaches, say, 5%?
> >
> > I just ordered a few laptop battery replacements
>
> I guess you're talking about Lithium ion or Lithium polymer batteries
> (as all modern devices are using either of those)? Then you do rather
> *not* want to deep discharge them often, or at least not leave them in
> this state for a long time. They are said to live longest when about
> half full. Unlike NiCd batteries they exhibit no memory effect, so
> there is no use for deep discharge except occasionally to let the
> electronic fuel gauge recalibrate itself so that the displayed charge
> percentage is correct. Aside keeping them half full and keeping them
> at cool temperatures, you can do nothing to prevent those batteries
> from loosing capacity over time, they age whatever you do.

I was going to post exactly this opinion earlier in the day when a 
work-related issue interrupted me. I'm not going to claim engineering 
level expertise in this matter, but I've been using laptop / notebook 
computers as my primary systems since the time when they first became 
available. IIRC deep discharge cycling of these more recent batteries is 
not what you want to prolong their life-spans. That was the game we 
played with NiCad batteries to prevent them from developing "memory" 
issues which caused them to think they were low on charge when they were 
actually at 40-50% charge. The newer battery and battery charging 
circuit technologies have rendered that strategy obsolete, I think.