A battery cover assembly includes a back cover, a battery cover and at least one elastic device. The back cover includes a battery chamber recessed there-into and an separation-preventing portion protruding therefrom. The battery cover is slidably mounted on the battery chamber of the back cover and includes an anti-detaching portion protruding therefrom. The anti-detaching portion is configured for being blocked by the separation-preventing portion to avoid the battery cover being released from the back cover when the battery cover is slid relative to the back cover. The elastic device has two opposite ends secured to the back cover and the battery cover respectively. The elastic device is configured for providing an elastic force to open the battery cover relative to the back cover.