Taking Ubuntu’s Battery Warnings With a Grain of Salt
There have been quite a few complaints about battery life with Ubuntu, and I’ve made a few myself, but it seems that the battery life may not be quite as bad as the operating system would have us think. A little while ago I had talked about how I accidentally discovered that my battery life with Ubuntu 7.10 was actually superior to Windows XP, and I’ve been looking for some ways to easily tweak the warning messages ever since. Unfortunately, short of re-writing some code, I don’t see an easy way of correcting the display problem.
But there is hope!
I’ve been running on battery power whenever possible over the last few days in order to determine exactly how long my notebook can run and it right now stands at approximately an hour and forty-five minutes. This is a nice twenty-five minute boost over the best Windows XP run time, and doesn’t even require me to shut off the wireless or Bluetooth radios. Not bad for a 4 year old notebook and with original battery. However, in order to actually get this amount of run time, you need to be willing to have your notebook shut off at any second.
I get the first “Laptop battery low” message after 50 minutes of normal usage. “Normal” for me means everything from writing PHP, Ruby or Java, to watching Futurama episodes over a wireless connection. Rarely do I use the optical drive or PCMCIA slots, but everything else is used quite regularly. The critical message is usually received fifteen minutes after the first, and usually has a pretty scary battery life estimate.
Who knew we could get 4 minutes from a dead battery?
Oddly enough, once I receive this warning saying I have 0% battery remaining, I can usually get another half-hour of use from the notebook. It’s not until the power LED on the computer starts to flash red in warning that I get nervous. So this begs the question: why does the notebook battery life estimate differ so much from Ubuntu’s?
Unfortunately, I can’t find that answer. All I can say for sure is that this little discrepancy often gets me an extra half hour of usage over what the operating system says I can do. Perhaps this will be corrected in a future version of Ubuntu, or maybe it’s just one of those little quirks that some of us have because we’re using older technology. Either way, you can’t believe everything your computer tells you.
Have you run into this problem in the past? Do you have any suggestions how I might get Ubuntu to properly read the remaining battery power?
Comments (8)
No suggestions, not even sure if I’ve had this exact problem, but I’ve noticed some funny things when it comes to the battery. I thought mine was draining too fast one time.
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When I first installed Ubuntu the battery would drain incredibly quickly. However, after setting laptop-mode-enabled to true, the hard drive would spin down when not connected to an outlet. That alone saved a good 45 minutes of power.
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Hmm… with Kubuntu on my laptop the battery meter seems to be just in line with the flashing red light on my laptop. Mine is a Dell Inpsiron 1501. Maybe that has something to do with it.
@Jason, where is that setting?
Mike, you can find it as the last line in your /etc/defaults/acpi-support file. You can get there through the terminal by typing:
sudo gedit /etc/defaults/acpi-support
The very last line will read “laptop-mode-enabled=false”. Simply change the false to true and you’re good to go. The next time you restart, laptop mode will be enabled.
That said, make sure you’re using Ubuntu 7.10 or greater as there were some problems with laptop handling in 7.04 and below. They were all fixed for the 7.10 release, though
I apparently don’t have the program “Defaults” installed, nor do I have that folder in /etc.
I’ll post an article with detailed instructions on how I made my Ubuntu install notebook-friendly in a day or two. That should clear things up a bit, I hope
Mike: It’s /etc/default/acpi-support, not /etc/defaults/acpi-support.