CHARGING SYSTEM, METHOD AND DEVICE FOR CONTROLLING CHARGING SYSTEM, AND ELECTRONIC DEVICE

A charging system includes: a power management integrated circuit, a bidirectional voltage conversion circuit, a controller and a battery level detection circuit. The bidirectional voltage conversion circuit is configured to work in a working mode including at least a boost mode and a buck mode. The controller has a first terminal. An input terminal of the battery level detection circuit is connected to a battery, an output terminal of the battery level detection circuit is connected to the first input terminal of the controller, and the battery level detection circuit is configured to detect a voltage and a current of the battery and transmit the voltage and the current of the battery to the controller. The controller is configured to control the working mode of the bidirectional voltage conversion circuit and a working state of the power management integrated circuit according to the battery voltage and the current.