Amazon.com: Synergy Digital Dog Collar Battery, Compatible with Dogtra BP12RT Dog Collar, (Ni-MH, 4.8V, 400 mAh) Ultra High Capacity, Replacement for Dogtra 28AAAM4SMX Battery : Electronics
Replacement Battery for Dogtra Receivers & Transmitters - Battery Warehouse
Amazon.com : Dog Training Collar Transmitter Battery Replacement for Dogtra 1900 NCP - Compatible with Dogtra BP12RT (300mAh, 4.8V, NI-MH) : Pet Supplies