You can close batches whenever you wish and it is very easy to do so!
From the List>List & Prep page, locate the batch name under Open Batches and click the icon with three horizontal lines next to it.
This drop-down menu gives you 3 options: One is a Pencil (for editing the batch name), one is a Printer (for printing all labels), and the other is an X (to close the batch).
Click the X to close the batch.
Once you have confirmed you have closed the batch, you can always view it again by going to List>Closed Batches.