Re: Battery life

[Derek Broughton <derek@pointerstop.ca>]

On Monday 21 March 2005 13:15, Jan T. Kim wrote:
> On Mon, Mar 21, 2005 at 10:39:19AM -0500, Steven wrote:
> > Huh! And I was advised the opposite recently by a fellow tech.
> > He claimed leaving the battery in and constantly charged would result in
> > longer battery life span.
>
> If I recall correctly, the question is to which extend the battery is
> kept charged, and in what increments. The c't story was:
>
>     * for longest life, batteries should be charged to 80% of their
>       capacities. Apparently, notebook manufacturers sometimes keep
>       stocks of batteries that they keep charged at that level, to be
>       sold as replacements when the model is no longer made.
>
>     * deep, total discharge of the batteries must be avoided
>
>     * the number of re-charges should be minimised
>
>     * exposing the battery to higher temperatures, such as those in a
>       working notebook, accelerates deterioration
>
>     * temperature induced deterioration is worse if the battery is fully
>       charged.

Unfortunately information on the best ways to treat batteries is often 
contradictory.  My laptop came with instructions to store unused batteries at 
40% charge, and I've heard that deep discharge of L-ion batteries is not a 
problem.
-- 
derek