I have Ubuntu 10.04 in VirtualBox. If I have the address correct this should work.
You can click on:
System > Preferences > Startup Applications -> in the "Startup Programs" tab click on the "Add" button, then browse to the "File System" folder (/etc/xdg/autostart/gnome-power-management.desktop), and click "Open" (this will enter the address in the Command Address space).
Type "Power Manager" in the "Name" space and then click on the "Add" button. This should return Power Management to the Startup Applications Preferences. If you have removed it totally, you may have to use a live cd to load from.
If that does not work, a less than desirable way is to click on the "Options" tab in "Startup Applications Preferences." Having only the minimum apps running including "Power Management" and click on 'Remember Currently Running Applications' or 'Automatically Remember Running Applications when logging out', the application should run the next time you logon.
- In the Terminal, enter "gconf-editor," click "enter," then in the left pane, expand apps, scroll down and expand gnome-power-manager and click notify. A list of possible notifications will appear in the right pane. Clicking on the options will bring up a description in the lower right part of the screen. Also check /schemas/apps/gnome-power-manager/notify (same editor).
- You can open "Power Management," click on the 'General' tab, then click on 'always show icon' if that has failed.
You can right-click on Power Management" and then 'add this launcher to panel' this at least will place it on the panel.
Or from this link you can check if the battery status is available for Ubuntu 9.10, 10.04 and 10.10 via the following PPA:
sudo add-apt-repository ppa:iaz/battery-status and
sudo apt-get update
sudo apt-get install battery-status
The applet will, initially, run as a standard gnome applet. To initiate 'indicator applet' mode, you will need to run the following command in a terminal:
This information came from here and more information here. Step 1's information came from here.