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.