PetSafe RFA-18 Replacement Battery vs PetSafe RFA-188 3 Volt Replacement Battery

These are not interchangeable. The RFA-18 is a 6V battery for the RFA-67 receiver, while the RFA-188 is a 3V CR1/3N cell for Little Dog fence receivers and several bark collars. Buy the one your collar or receiver specifies; the wrong voltage will not power the unit and may damage it. Owners of the RFA-188 rate it modestly at 3.8 out of 5, with the common complaint being short runtime of about a month.

• Choose the PetSafe RFA-18 if your receiver takes the RFA-67 6-volt battery pack and you want a sealed, waterproof unit with caps included.
• Choose the PetSafe RFA-188 if your collar or fence receiver specifies a 3V CR1/3N cell and you want a long shelf life between changes.