Dell Latitude D600 & Ubuntu: Force ACPI to Use Both Wireless and Battery Meter by David Whelan I spent a lot of time trying to get this laptop to properly use the wireless card. You can see my travails on another post. But once I got the Intel Mini PCI B 2100 wireless card working using the ACPI=OFF switch in my Grub boot file, I could no longer see what was going on with my battery. This is a problem because the batteries I have are old and run down quickly. I seem to have found a solution that enables me to use both wireless AND monitor my battery level.
There’s not that much more to say. Instead of leaving the line in your Grub2 file – at /etc/default/grub – as acpi=off, try converting it to acpi=force. When I restarted, my battery icon immediately appeared on the top panel.