On my Dell Vostro 3450 with i5 2410M Ubuntu can work over 4 hours without any power supply. I just had to force ASPM to work and put "echo powersave > /sys/module/pcie_aspm/parameters/policy" in /etc/rc.local. I know it's an awful hack, but it works. Something should be done about it. Battery lifetime should be maximized out of the box.
On my Dell Vostro 3450 with i5 2410M Ubuntu can work over 4 hours without any power supply. I just had to force ASPM to work and put "echo powersave > /sys/module/ pcie_aspm/ parameters/ policy" in /etc/rc.local. I know it's an awful hack, but it works. Something should be done about it. Battery lifetime should be maximized out of the box.