A charging system includes: a first battery, a second battery, a switch device, a charging component, and a control component. A capacity of the second battery is smaller than that of the first battery. The switch device is disposed outside the second battery and connected to the second battery. The charging component is connected to the first battery and connected to the second battery via the switch device, and configured to output a charging current to the first battery and the second battery. The control component is connected with the first battery and the second battery, and configured to detect remaining capacity of the first battery and the second battery during a charging process and control the switch device to turn on or turn off based on the remaining capacity.