One For All - The Finder Remote Control (15-1940) Batteries Faxback Doc. # 38543 The Finder comes with its own batteries for both the Transmitter and the Receiver. The batteries in both items should last over a year. In the event that you would need to change the batteries in one or both of the items, here are the types of batterie s you will need: The Transmitter: (1) 9 volt Battery The Receiver: (1) 3 volt Lithium coin cell battery (EB 3/24/97)