For example, Roomba i1, i3, i6, i7 and the e series use an 1,800 mAH (milliamp hour) Li-ion battery, whileRoomba i4, i8 and j7 use a 2,210 mAH Li-ion battery, providing those models with longer battery life or more power to run their features. TheRoomba s9and its variants use...