Electricity supplementing equipment and method for transferring electric quantity of double electric vehicles

The invention discloses a charging device and method for electric quantity transfer of double electric vehicles, and belongs to the field of new energy, the charging device for electric quantity transfer of double electric vehicles comprises a direct current charging gun, a double-ring charger and a controller; a controller is installed in the double-ring charger, and a direct-current voltage output port of the double-ring charger is connected with the direct-current charging gun. The charging module adopts a modular design, and is formed by connecting a plurality of direct current-direct current charging modules in parallel, so that the cost of the charging equipment can be reduced, and the convenience of assembly and maintenance is improved; the efficiency curve of the charging module has a great relationship with the input and output voltage and power, and an optimal point tracking algorithm is adopted to automatically set the voltage regulation output and the working number of the direct current-direct cu