Re: Low-Level and Long-Term Battery Control

[Pavel Machek <pavel@ucw.cz>]

On Thu 2010-04-15 16:42:56, David Rees wrote:
> On Thu, Apr 15, 2010 at 11:02 AM, Pavel Machek <pavel@ucw.cz> wrote:
> >> For Laptops, it is better to extract the battery from the Laptop when
> >> the computer will be on power for a long period.
> >> I ask if the kernel can do such control without the user intention and
> >> in an automatic way.
> >>
> >> Some BIOS provide to the user to select whether to block the battery
> >> charging to 50% to make it stand for more time.
> >
> > Where have you seen that?
> 
> I do recall that some older ThinkPads had a utility that would let you
> determine what "empty" and "full" was by setting artificial limits.
> It's well known that by keeping batteries from being fully
> charged/discharged can significantly extend it's useful life although
> you will suffer from shorter run-times.  How sensitive a battery is to
> this depends on it's exact chemistry, but all are affected by this to
> some degree.
> 
> For example, by keeping your battery from charging above 85% and below
> 15% can increase the number of charge/discharge cycles a large
> amount

>From charging below 15%?

> often on the order of 5-10 times more charge/discharge cycles - much
> more than the 30% reduction in total capacity.  Limiting to 25-75%
> will help even more.

I believe I've seen "don't charge above 85%", but "don't charge above
50%" is quite excessive...

Anyway, this is done by smartbattery, not by OS.
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html