HQRP Battery for Sportdog Sport-Hunter 1800 SD-1800 Remote Controlled Dog Training Collar Transmitter plus Coaster HQRP&reg; Rechargeable Battery plus HQRP&reg; Coaster; Battery Voltage: 7.2V; Capacity: 330 mAh; Ni-Mh; Compatible with Original Battery; 200 Days warranty!