Unfortunately there is no mobile device battery model by default.
However, you can extend the code to track battery life.
For example, the mobility model manages such treemap to determine mobile device location over time.
private List<TreeMap<Double, Location>> treeMapArray;
For example, this data structure holds the following data if the 3rd mobile device stays at Location1 for 15 seconds, then moves to Location2 and stays there for 20 seconds.
[ 3, [<15,Location1>, <35,Location2>] ... ]
You can define a mobile device battery model by manipulating the similar data structure.
If you only need the current battery level, you don't have to maintain the battery level over time.
A simpler data structure (2 dimentional list) may meet your needs.