I have an annoying little problem on my Compaq Presario 710 laptop. This problem has been around in every version of linux I use on it. It persists in Fedora Core 4. The battery monitor applet shows the percentage of the battery faithfully, but continues to remain at the power connection status that it had at login. when I unplug or replug the cord, it remains at AC or battery, depending on which state is was in at login. The only change is that it will switch between "charging" or "AC power" depending on whether or not the battery is at 100%

Is there some service or kernel module I need to start/load?

First time I installed the SUSE 10 on my ASUS A2H, I had the same problem ( I used the Gnome desktop) then, I deleted SUSE and reinstalled it again but this time with KDE! believe me, I liked it more with KDE!
Well, the problem wasn't resolved yet! till I made a full update to the SUSE and I was surprised after I rebooted that the battery monitor is working very well! even better than in WindowsXP.

--In windows, when charging the battery, it shows that it is full! till 98% then it will show that it's charging till the 100%. Suse gives me the true status all the time.--

Try to update your Distro and try to look in the laptop packages for what it could be useful for your Laptop.
Just a thought, try to check (in the control center) the battery and power control devices drivers.

Good luck

fedora core 4 doesn't do ACPI well so battery monitor wont be effective. Check for updates to kernel that improve ACPI support.You would need latest BIOS too. Kde utilties include klaptodaemon and ksim. Gnome may have parallel utilities.If no ACPI, APM utilities may work. Google is your friend

I looked on google, there didn't seem to be anything relevant. I am currently waiting on a set of ubuntu CDs. Does ubuntu do ACPI better? I may use RHN to update everything on my system next time I can access the Internet broadband at school.

Thanks for all the help, I will post back if I get it to work.

Ubuntu and Suse are among the best for doing ACPI and wireless on reboot. Debian Etch/Sid and Kanotix 2005-04 with a little coaching should too. Remember that Compaq lappy is an older model so the BIOS may not do ACPI too well. APM can do battery monitoring too depending on lappy and BIOS. Good luck.

OK thanks. I am waiting on Ubuntu CDs in the mail. Hopefully it works better

I had the same problem running Ubuntu and it happens to be a kernel problem, I've made a path and now it works. The problem was in the Embedded Controller driver that controls the "messages" from the battery, it makes an active waiting rather than using interrupts, and it seems some circuits doesn't like one option or another.
If you want the patch i'll send you, but you will need to recompile the kernel, and maybe it wont work in your machine