The battery indicator in Unity panel not showing up
I've just installed Ubuntu 12.04 on my Acer Aspire 5553. It's the first time I've used Linux for more than 4 years so I don't really know what I'm doing. The installation went almost perfectly; Internet connections and graphics were all configured fine (which is more than I can say for the Windows 7 I've just installed on a dual boot).
However, when I unplug the power supply, there is no battery indicator displayed. In the power settings, there is only one column; I've seen screenshots indicating that I should see two columns, one for "On battery power" and one for "When plugged in". There is also no field "When power is critically low".
I can use the laptop on battery power, but it just keeps running on full power until it suddenly switches off. It seems like the OS doesn't "know" it's on a laptop.
I installed Windows 7 yesterday on dual boot and that configured the power supply perfectly (unlike most of the other hardware).
I reinstalled 12.04 this morning and the problem persists.
The problem is there in both Unity and Gnome.