BatteryBar is one of the best free battery meter software you can find for display information about the status of your laptop battery. The current stable version of BatteryBar is 3.5.7 released on June 1, 2013. Currently this software only runs in windows so, bad luck for the users who uses different platform. It also has a paid version which has more features if you're interested. But the free version just work fine for me. It's more accurate than the built in battery meter for windows and display whole lot more details.