Long Lasting Linux Laptops?

[Mark J. Dulcey]

On Fri, 24 Mar 2000, John Abreau wrote:

> I'm running Linux on a Sony Vaio C1X with a Novatel Wireless Merlin
> cdpd modem, and I love everything about this machine except one thing:
> the battery life really sucks. It came with a "3-hour" battery which
> lasts just about an hour, so I it the bullet and bought the "6-hour"
> battery, which lasts about two hours.
> 
> I find this frustrating enough that I'm almost considering replacing it,
> if I can find something with a reasonably long battery life. What kinds
> of battery life do you find on your laptops? What's the longest actual
> battery life you've seen in a laptop?

First question: do you have APM installed on your laptop? (Note: neither
RedHat nor SuSE comes with APM on by default.) Battery life is going to be
terrible without it. Your laptop will also run cooler with APM enabled,
because Linux will actually halt the CPU when it's not doing anything
(typically 80-90% of the time), and the hard disk will spin down after
being idle for a while.

It also helps to change your cron settings. The defaults will keep waking
up the HD as the system checks for crontab changes. I don't remember the
details right now.

And it's not clear anything will help if you insist on using the CDPD
modem. Many PC cards are power hogs, and anything that transmits is likely
to be an especially bad hog. Depending on the design of the modem
(whether it can be powered down when not in use), APM may or may not help.

I can actually get close to four hours out of my HP Omnibook 5000. True,
that is with TWO Li-ion batteries installed... but each one does deliver
the two hours it's supposed to. On the other hand, the thing is a crufty
old P90 with a measly 800x600 256-color display.


-- 
Mark J. Dulcey               mark at buttery.org
Visit my house's home page:  http://www.buttery.org/
Visit my home page:          http://www.buttery.org/markpoly/

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