Needs-more-power asks: My laptop battery doesn't last as long when it's running Linux. How can I get more life out of it?
It may sound obvious, but the easiest way to extend your battery life is to reduce the number of features you're using. For example, if you're performing tasks that don't require an Internet connection, turn off your WiFi:
# Get a list of wi-fi device names
# Turn off wi-fi
iwconfig <device_name> txpower off
# Turn on wi-fi again
iwconfig <device_name> txpower on
If you're using your laptop to watch movies during a trip, rip the DVDs to your hard drive ahead of time so the machine isn't wasting power spinning the disc. When appropriate, dim the screen a little in your system settings.
Some more technical solutions include disabling access time stamps on files which will reduce the number of writes to the hard disk. You can do this by adding the noatime flag to your fstab entries. Assuming you're doing simple work where you don't need to use all of your CPU cores, try running the following command as root to enable scheduler power savings:
echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
You might also consider using a lighter desktop environment, like LXDE, instead of GNOME or KDE. Likewise, disable any services (such as Bluetooth) you don't need at the time. Another thing to keep in mind is it seems recent versions of the Linux kernel use more power than earlier versions, so a distro running the 2.6.32 kernel might be better for your battery than a 2.6.38 kernel.
On long trips where you need to work and the battery just isn't living long enough, consider buying a back-up battery. Sure, it's not a technical solution, but it's a simple one and it doesn't hurt to have a spare.
**Extending battery life**