A battery-cleaning device is disposed on a casing of an electronic device. The casing has a battery slot which can receive at least one battery within. The battery-cleaning device comprises a rod, a spacer and a plate sheet. The rod is disposed on the casing movably. The spacer is fixed on the rod, and can be moved with the rod. The spacer extends to the battery slot, and is adjacent against to the surface of the battery. The plate sheet has at least one scrape part, and is disposed at the end of the battery. The device rotates the battery by the spacer, and scrapes the dirty things on the end of the battery. The device can clean the battery and prevent it raising the impedance.