A charging method of controlling output voltages, comprising: acquiring, by a controller, a first mapping relation that is a one-to-one mapping relation between at least two adjustment strategies and at least two duty cycles, wherein each of the at least two adjustment strategies comprises indication information of an adjustment direction of an output voltage of a power converter, wherein the output voltage is used for charging a battery; determining, by the controller, a first adjustment strategy; generating, by the controller, a pulse width modulation, PWM, signal based on the first adjustment strategy and the first mapping relation, wherein a duty cycle of the PWM signal is one of the at least two duty cycles indicated by the first mapping relation and corresponds to the first adjustment strategy; transmitting, by the controller, the PWM signal to a low-pass filter; generating, by the low-pass filter and based on the PWM signal, a voltage feedback signal, and transmitting, by the low-pass filter, the voltage feedback signal to the power converter; and adjusting, by the power converter, the output voltage of the power converter corresponding to the voltage feedback signal, characterized in that determining, by the controller, the first adjustment strategy comprises: receiving, by the controller, control information transmitted by an external device, wherein the external device receives the output voltage and the control information comprises indication information of a battery temperature of the external device and indication information of a battery power level of the external device; determining, by the controller, a safe voltage range and a safe current range based on the external device; and determining, by the controller, the first adjustment strategy based on the control information and satisfying the safe voltage range and the safe current range, such that an adjusted output voltage based on the first adjustment strategy is within the safe voltage range and such that an adjusted output current based on the first adjustment strategy is within the safe current range. acquiring, by a controller, a first mapping relation that is a one-to-one mapping relation between at least two adjustment strategies and at least two duty cycles, wherein each of the at least two adjustment strategies comprises indication information of an adjustment direction of an output voltage of a power converter, wherein the output voltage is used for charging a battery; determining, by the controller, a first adjustment strategy; generating, by the controller, a pulse width modulation, PWM, signal based on the first adjustment strategy and the first mapping relation, wherein a duty cycle of the PWM signal is one of the at least two duty cycles indicated by the first mapping relation and corresponds to the first adjustment strategy; transmitting, by the controller, the PWM signal to a low-pass filter; generating, by the low-pass filter and based on the PWM signal, a voltage feedback signal, and transmitting, by the low-pass filter, the voltage feedback signal to the power converter; and adjusting, by the power converter, the output voltage of the power converter corresponding to the voltage feedback signal, characterized in that determining, by the controller, the first adjustment strategy comprises: receiving, by the controller, control information transmitted by an external device, wherein the external device receives the output voltage and the control information comprises indication information of a battery temperature of the external device and indication information of a battery power level of the external device; determining, by the controller, a safe voltage range and a safe current range based on the external device; and determining, by the controller, the first adjustment strategy based on the control information and satisfying the safe voltage range and receiving, by the controller, control information transmitted by an external device, wherein the external device receives the output voltage and the control information comprises indication information of a battery temperature of the external device and indication information of a battery power level of the external device; determining, by the controller, a safe voltage range and a safe current range based on the external device; and determining, by the controller, the first adjustment strategy based on the control information and satisfying the safe voltage range and the safe current range, such that an adjusted output voltage based on the first adjustment strategy is within the safe voltage range and such that an adjusted output current based on the first adjustment strategy is within the safe current range.