CPU Utilisation feedback

On Macbook 12” - 8Gb ram. App is responsive, works well - see that it is always using 5-10% CPU even when idle. Have purchased pro version so I can edit calendars and reduce those. what is driving this CPU usage constantly? I need battery long life so anything that is always chewing CPU is something I always want to optimise.

There should be very little usage if the app is finished syncing and in the background. Just checked now, and Agenda is at 0% for me in the background.

Does it help to go into the Agenda Preferences and select the calendars you are using there? Are there a lot of calendars in the list?