the housing 21 defines a battery cavity 211 and a groove 212 the battery cavity 211 is for receiving the battery 22 a slot 2121 is defined on the base of the groove 212 for receiving the sliding button 10 and the locking member 11 and thus the sliding button 10 and the locking member 11 can slide in the groove 212 near to the groove 212 a sidewall 2111 of the cavity 211 includes a first hollow 2112 and a second hollow 2113 configured for passing through the first pushing part 129 and the second pushing part 120 respectively the housing 21 further defines a protrusion 214 and a pothook 213 on its undersurface the protrusion 214 matches with the third hook 114 the pothook 213 is configured for clasping the second clasp 132 the battery 22 includes a battery body 220 and a connection end 221 extruded from the battery body 220 the connection end 221 includes a first supporting member 222 a second supporting member 223 and an unlocking member 224 the first supporting member 222 and the second supporting member 223 are respectively for supporting the first pushing part 129 and the second pushing part 120 the unlocking member 224 includes a chamfer 2241 a notch 2242 is formed in the end of the chamfer 2241 fig4 7 are schematic diagrams.