An electric wheel hub, including: a shell , including a base and a cover, the base defining an interior space and a mounting entrance , the cover being mounted to the base in a mounting direction and covering the mounting entrance ; a motor assembly , including a stator , a rotor and a shaft , the stator and the rotor being received within the shell by moving through the mounting entrance in the mounting direction , the stator and the rotor being relatively rotatable, the rotor being connected with the shell , the shaft being disposed within the shell in a direction opposite to the mounting direction and disposed through and connected with the stator , two ends of the shaft being configured to be respectively connected to two fork arms , the shaft defining an axial direction and a circumferential direction , the shaft and the stator being relatively movable in the axial direction , the shaft and the stator being relatively non-rotatable in the circumferential direction ; and a battery unit , electrically connected with the motor assembly , including a cartridge and a plurality of batteries , the plurality of batteries being positionally received within the cartridge , the cartridge being received within the interior space by moving through the mounting entrance in the mounting direction , the cartridge being connected with the stator and disposed around the motor assembly characterized in that : the battery unit further includes an attachment portion , the cartridge is annular and includes a receiving space , the attachment portion is connected with cartridge and extends from a first end of the receiving space , the motor assembly is received within the receiving space by moving into the receiving space from a second end of the receiving space , the first end is more adjacent to the cover than the second end , and the attachment portion is connected with the stator . a shell , including a base and a cover, the base defining an interior space and a mounting entrance , the cover being mounted to the base in a mounting direction and covering the mounting entrance ; a motor assembly , including a stator , a rotor and a shaft , the stator and the rotor being received within the shell by moving through the mounting entrance in the mounting direction , the stator and the rotor being relatively rotatable, the rotor being connected with the shell , the shaft being disposed within the shell in a direction opposite to the mounting direction and disposed through and connected with the stator , two ends of the shaft being configured to be respectively connected to two fork arms , the shaft defining an axial direction and a circumferential direction , the shaft and the stator being relatively movable in the axial direction , the shaft and the stator being relatively non-rotatable in the circumferential direction ; and a battery unit , electrically connected with the motor assembly , including a cartridge and a plurality of batteries , the plurality of batteries being positionally received within the cartridge , the cartridge being received within the interior space by moving through the mounting entrance in the mounting direction , the cartridge being connected with the stator and disposed around the motor assembly characterized in that : the battery unit further includes an attachment portion , the cartridge is annular and includes a receiving space , the attachment portion is connected with cartridge and extends from a first end of the receiving space , the motor assembly is received within the receiving space by moving into the receiving space from a second end of the receiving space , the first end is more adjacent to the cover than the second end , and the attachment portion is connected with the stator . <EOS>