I previously wrote about reducing CPU usage for Firefox by disabling Firebug. Later, I wrote on disabling the YSlow extension also reducing CPU usage.
Now, the laptop is able to exceed 4 hours of battery time under Kubuntu Linux 12.04:
Four hours, seven minutes:
09:37:27 localhost pm-utils: Power source switched to battery, Battery: discharging, A/C adapter: off-line
How often do you reboot your laptop?
Well, for me, I run Linux (Kubuntu 12.04), and I usually do it when a new kernel security update is released. And put it on sleep otherwise.
This means I can go for a month and a half without rebooting.
Here is a recent example, output from the "uptime" command:
14:31:46 up 45 days, 2:10, 7 users, load average: 1.45, 1.29, 1.28