Battery indicator is stuck on "estimating"?
Solution 1:
This is known bug that affects HP, Compaq, Dell and other manufactures. This is because of a change made in gnome-power-manager where by the estimate is done on time remaining, rather than percentage. This change does not play nice with some hardware and is why you are seeing (estimaing...) constantly.
The bug report about it is here if you fancy a read: https://bugs.launchpad.net/ubuntu/maverick/+source/gnome-power-manager/+bug/629258
At this time, I believe there is no fix available. However you can click on the estimating... and it will bring up a more detailed view of your battery info, which will display the percentage of charge.
Solution 2:
Battery Status is a good alternative applet that will show the battery percentage.
http://www.webupd8.org/2010/11/battery-status-ppa-finally-updated-with.html
Run these two commands to install a ppa for the new indicator:
sudo add-apt-repository ppa:iaz/battery-status && sudo apt-get update
sudo apt-get install battery-status
Now start the new battery indicator (it will replace the default indicator for future logins):
nohup /usr/lib/battery-status/battery-status --indicator &
If this bug affects you, say so at the bug report:
https://bugs.launchpad.net/ubuntu/maverick/+source/upower/+bug/629258
Solution 3:
Bug: https://bugs.launchpad.net/ubuntu-release-notes/+bug/629258
Entry #91 fixed my x64 HP Pavilion:
Steps to apply @Brian's PPA update:
1) From a terminal window:
sudo add-apt-repository ppa:brian-rogers/power
sudo apt-get update
sudo apt-get upgrade
2) Reboot
3) Login normally, click on the battery icon