Why Is Linux Notebook Battery Life Still Poor?

Ganty writes "I recently purchased a Lenovo W500 notebook, and after 'downgrading' to XP and creating a dual partition, I found that I had a battery life of nearly three hours using the long-life battery, at this point I was a happy camper because it means that I can watch a DVD during a flight. I then tried various Linux distributions and found the battery life under FOS to be very disappointing, with an average of 45 minutes before a warning message. After settling on Ubuntu I then spent three days trying various hardware tweaks but I only managed to increase the battery life to one and a half hours. Unwanted services have been disabled, laptop mode has been enabled, the dual core CPU reduces speed when idle and the hard drive spins down when not needed. Obviously Apple with their X86 hardware and BSD based OS have got it right because the MacBooks last for hours, and a stock install of MS Windows XP gives me three hours of life. Why is battery life on notebooks so poor when using Linux? Some have suggested disabling various hardware items such as bluetooth and running the screen at half brightness but XP doesn't require me to do this and still gives a reasonable battery life."

Comments

RTFM

[eln]

I don't know how you can expect us to fix your problems when you won't even take the time to read the documentation provided with the release.

In order to solve your problem, you need to set the RANDOMLY_DISCHARGE_BATTERY flag in the kernel source to "0" at compile time. Ubuntu, as well as other "desktop" distributions, set this flag to "1" by default for some reason, but simply installing the source packages and recompiling your kernel will fix the issue.

Honestly, a simple well-tailored Google search and a few measly days of sifting through the docs would have given you this answer without having to waste everyone else's time.

Re:RTFM

[Rhaban]

it hasn't?

Re:RTFM

[Shakrai]

In order to solve your problem, you need to set the RANDOMLY_DISCHARGE_BATTERY flag in the kernel source to "0" at compile time. Ubuntu, as well as other "desktop" distributions, set this flag to "1" by default for some reason, but simply installing the source packages and recompiling your kernel will fix the issue.

Recompile the kernel? You n00b. Just add this to your rc.local file:

echo 0 > /proc/sys/kernel/randomly_discharge_battery

Re:RTFM

[Khyber]

If you actually bothered to THINK about it - all operations of a computer are random power discharges.

therefore, it's not an option on compile - the compiler automatically puts it in without you needing to say so! That's the POWER OF LINUX!

hah!

[neo]

He only wasted you time and informed me and about everyone else who didn't know this. Thanks eln!!

Re:power saving tip: disable the optical drive

[Yvan256]

Go a step further - read a book.

Re:power saving tip: disable the optical drive

[Anonymous Coward]

Jerkwad.

Re:power saving tip: disable the optical drive

[Shakrai]

Go a step further - write a book.

No...

[msauve]

kernel developers are smarter than that, and know that would be impossible to support. The real flag is PSEUDO_RANDOMLY_DISCHARGE_BATTERY.

Re:No...

[Anonymous Coward]

PSEUDO_RANDOMLY_DISCHARGE_BATTERY

ermmmm.... you mean sudo PSEUDO_RANDOMLY_DISCHARGE_BATTERY?

Re:power management

[Anonymous Coward]

Oh, hey, I know you. You're the tech support guy from A&TT I spoke with last week. When I asked why my cell phone didn't turn on anymore, you asked me to turn it on and go to the configure screen. When I responded that It wouldn't turn on. You asked me why.

No problems

[mgichoga]

What do you mean? I just turned on my laptop linux and it always lasts ove

Re:Well duh

[Tubal-Cain]

Because linux is fucking terrible for desktop use.

The battery life on my desktop is just fine.

Re:Poor choice for screensaver?

[Anonymous Coward]

Thanks for that 3 year old article about an experimental kernel patch.

PS: this kind of absolutely useless advice is the reason the linux community eats big black shits

Re:Well duh

[rock217]

shocking that P & GP posted as AC

Re:Ditch Linux

[PouletFou]

Stop feeding the trollfeeders, you trollfeederfeeder!

Re:power saving tip: disable the optical drive

[IgnitusBoyone]

Ok, now everyone knows it takes far more energy to create a resource then it does to use a resource, We are trying to save ener

Re:Well duh

[Anonymous Coward]

Because linux is fucking terrible for desktop use.

The battery life on my desktop is just fine.

Really? Battery life on my desktop sucks. It dies as soon as I remove the power cord.

Re:power saving tip: disable the optical drive

[ThatsNotPudding]

Once you ripped the movie to a file

And if you're returning to the US from overseas, kindly ask the nice TSA people to charge up your laptop before taking you off to MPAA Prison.

Re:Poor choice for screensaver?

[Goaway]

Good old Linux community, where posting "I have this problem..." gets you the response "YOU DO NOT HAVE A PROBLEM! POST PROOF OR RETRACT!"

Re:Poor choice for screensaver?

[darthwader]

I have no idea what you are talking about. I don't have problems getting support on Linux from the Linux community.. Debian Ubuntu has the greatest and friendliest support people in the world.

Can you prove you got poor or non-existing support for Linux? Show us screen-shots, chat logs, and e-mail exchanges, or we won't believe you.

You want to hear about poor support? Try calling Microsoft tech support. They completely suck. I once called Microsoft tech support and I was on hold for 13 hours, and then I got connected to some loser who can't speak English. Of course I only called to swear at him, so I yelled abuse at him and hung up. But I had to wait 13 hours first. That sucks. If you want to yell abuse at a Linux support person, you can call Linus himself any time of the day or night, and he'll thank you for your suggestion.

The Linux community is great. I think you don't have any problems getting support for Linux, or if you do, it is because you are rude, stupid, and useless.