Battery Management

Battery management includes 8 tabs. Long-pressing one of them allows hidding it. Those are:

Status gives you an overall view of the current battery state and how and if battery data is being recorded.

Graphics shows you a graphical view of battery data if recorded.

History shows a text view of all recorded battery data.

Markers shows statistics of battery history based on markers (profiles, plug state, kernel/rom changes, etc)

Statistics shows battery statistics per app.

Estimates gives you overall run-time estimates considering your past usage pattern

Calibration allows to check battery capacity and helps you calibrate it if needed

Compare puts battery profiles side by side to compare battery performances against each other.

For information on how to extend your battery life, here is an interesting Wiki (see battery life chapter).

To extend battery life, the important points are those 2:

Keep battery cool, and avoid charging past 70% while using the device and creating over-heating.
You can discharge your battery fully (voltage going down to 3200mV) it won't hurt as 3200mV actual means 40% of battery capacity is left, which is the safe threshold mentioned in the Wiki above!

In all screens additional options are available pressing the menu button in action bar: