Basically, the camera works with any power bank. Here the maxim is that the more mAh, the longer you can use the camera. The camera itself has a small 700 mAh battery built-in. So a 2,000 mAh power bank should theoretically provide 3 x 2.5= 7.5 video hours of additional battery life. For the C2: We recommend opting for an extra-long cable. We offer a 5-meter charging cable so you can hang the camera wherever you want.