I can't believe I've never seen it in Ubuntu but something possessed me to look at power manager today and I found a few new goodies. This feature reminds me of perfmon in Windows only for power manager. It shows a lot of information regarding power management such as: power history, voltage history, charge/discharge time profile, charge/discharge time accuracy. It presents a nice graph with trends. This is another great way to see the performance of your laptop battery and one more plus for Ubuntu!