I am using ubuntu 11.10. There was an option for the same in 11.04.
I found a suggestion listed here. Unfortunately, it does'nt work.
$ GSETTINGS_BACKEND=dconf gsettings set org.gnome.power-manager icon-policy charge
No such key 'icon-policy'
Manually creating icon-policy key & setting it to "charge" might help, however I did it from terminal & it worked fine for me(both in gnome-shell & fallback mode).
Run update manager & make sure you have latest updates.Disable any extension(if you have any) related to power or battery.Then open terminal & run following command:
it should return something like these:
Now set the icon policy to charge:
Does this help?
Update: This above method only works with gnome 3.1.3 or less.
Unfortunately in latest gnome this isn't possible any more. "
If you want to hide battery icon in gnome shell, see this post: how to remove battery indicator in gnome-shell?
On Unity, support for hiding of icon and settings has been added with indicator-power - 1.90-0ubuntu1 (bug 811769).