Is the RunningAppProcessInfo the best way to determine apps that might use battery?

Is the RunningAppProcessInfo the best way to determine apps that might use
battery?

In my app, I just want to display the apps that are running and might
cause a battery drain at current time.
The first thing that comes in mind is the list of running processes:
ActivityManager activityManager = (ActivityManager)
this.getActivity().getSystemService(Activity.ACTIVITY_SERVICE);
List<ActivityManager.RunningAppProcessInfo> procInfos =
activityManager.getRunningAppProcesses();
Unfortunately, this list is huge and I am not convinced that so many apps
may be running at the same time, having a probability to cause a battery
drain.
I was just wondering if you think that this code might be enough or a
different approach might do the trick.
Thank a lot.