The invention provides a battery device used for an electronic cigarette.The electronic cigarette comprises an atomization device, and the battery device comprises a shell with a containing inner cavity, a power supply assembly, a liquid storage assembly and a connecting piece; the power supply assembly and the liquid storage assembly are both arranged in the containing inner cavity, and the connecting piece is arranged at the opening end of the liquid storage assembly, so that the atomization device can be inserted into the liquid storage assembly from the opening end and detachably connected with the battery device through the connecting piece.According to the battery device, the liquid storage assembly is directly arranged in the battery device, and therefore a user can complete connection of the atomization device with the battery device and the liquid storage assembly only through one-time connection in the installation process.The invention further provides the electronic cigarette with the battery device.