Dogtra RR Deluxe Dog Collar Battery (Ni-MH, 4.8V, 400 mAh) Battery - Replacement for GP - 28AAAM4SMX, GP - 40AAAM4SMX, Mighty Pets - BP-12, Sanik - 4SN-2/3AAA40H-H-XA1, Interstate - NIC0962 Batteries - Walmart.com
Amazon.com: iMah Ryme B40 4-Cell 4.8V AA Battery Pack with SM-2P Plug 2000mAh Ni-MH High Capacity for Radio Remote Control Car Off Road RC Trucks, Also Replace The Ni-CD AA 700mAh 4.8V
China Ni-MH Battery Pack (4.8V 550mAh) - China battery, battery pack
Amazon.com: iMah Ryme B40 4-Cell 4.8V AA Battery Pack with SM-2P Plug 2000mAh Ni-MH High Capacity for Radio Remote Control Car Off Road RC Trucks, Also Replace The Ni-CD AA 700mAh 4.8V