A battery cover assembly (100) includes a housing (10), a button assembly (20), a driving assembly (30), and a back cover (40). The button assembly includes a button portion (21) and a first latching portion (23). The back cover has a second latching portion (451). The driving assembly is configured for driving the back cover along a second axis. The button assembly is mounted on the housing and is movable along a first axis. The back cover covers the housing and is movable along the second axis. The first latching portion engages with the second latching portion in order to lock it to the back cover. When the button portion is pressed to move along the first axis, the second latching portion disengages from the first latching portion, and the back cover is moved along the second axis, under the force of the driving assembly.