iBatt is a very complete battery analysis tool for the Mac. It displays a lot of information about the current state of your battery and some historical information about it, too. Three main components make up this tool: the battery graph, three panes with information about the battery (battery status, extra info, health report), and two meters that display the charge and voltage of the battery.
The first component shows the charge level of the battery over time, and it starts when you first run the application. You can choose to view the graph in two modes: short- and long-term. This is useful if you have collected data over time and you want to switch between a detailed view and a historical view. Then, we have the three panes. These show information like battery model, manufacture date, current voltage, cycles, current charge, status, current capacity and design capacity, etc. The two meters show the current wattage of the battery and its charge. They look like speedmeters, and the needles move in real time.
In short, this is a nice application to check up on your laptop battery. It displays very useful and detailed information. The only thing I didn't like is that the app disappears when you switch to another application, even when you put it on a second monitor all by itself.