Having good, stable Fi Base connectivity is paramount to the accuracy of the Fi System and your dog's Fi Collar battery life. See: What Is the Best Connection Source for My Dog’s Fi Collar?
The Fi Base and the Fi Collar connect to one another via Bluetooth. Therefore, it is important that your base is set up in an area where the base can "see" the Fi Collar, see: Where Should I Set Up My Fi Base?
You can quickly and easily test your Fi Base coverage. See: How Can I Test Fi Base Coverage?