[ltp] [ltp]Questtion about battery

[Timothy Murphy]

On Wednesday 28 May 2008 01:34:27 pm Laurent Gilson wrote:

> > Sorry to be a skeptic, but is there any evidence that this
> > actually increases battery life?
>
> Read this:
> http://en.wikipedia.org/wiki/Lithium_ion#Storage_temperature_and_charge

Thanks very much.
That looks very informative, and I shall study it carefully.

At first sight, the figures for battery loss if charged to 40% or 100%
seem far too neat to come from experiment.
So I remain slightly skeptical.

> > I would have thought that if this was so
> > then battery/laptop manufacturers would have included this
> > as part of the standard operating system?
>
> You want a 100% full battery to work with, not 70%. So this is just
> for storing them, not for daily use.

You may, I don't.
If in fact there were a choice, say
"Normal Use or Long Life" I would nearly always choose the latter,
as I rarely work more than 30 minutes away from an AC supply.

I still find it extraordinary after all the hardware and software
that has gone into ThinkPad batteries and chargers
that there is not a simple switch for this,
if it would have the dramatic effect claimed:
"A Li-ion battery stored at 40% charge will last many times longer 
than one stored at 100% charge, particularly at higher temperatures."



-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland