After I installed Ubuntu 14.04 (before I had Ubuntu 13.10), the battery indicator stopped working properly. It always shows the battery level that was at the start up (when I open the laptop and boot Ubuntu), and is never updated. I checked the battery state in terminal by the command
acpi -V | grep Battery
and it works fine. So the is problem only with the battery indicator in the panel, not with the battery or the laptop. How to fix this problem?