I don't mean to infer the idea of a bad battery. It is possible a part of roomba's memory became corrupt and indicates there is a valid schedule. Pulling the battery will erase the memory. When I used to schedule my reds and disco, they would sometimes lose a schedule because of corrupt memory. One possible cause is static.
Reds x 3, Dirt Dog, Disco (now a parts bot), Create, Scooba 350, and Security Dawg