A system for controlling charge of a vehicle battery, comprising: a front wheel drive unit for driving a front wheel of a vehicle; a first high-voltage battery configured to supply electric power to the front wheel drive unit; a rear wheel drive unit for driving a rear wheel of the vehicle; a second high-voltage battery configured to supply electric power to the rear wheel drive unit; a bidirectional converter mounted within the vehicle and electrically connected at a first side thereof to the first high-voltage battery and at a second side thereof to the second high-voltage battery; a first charge port directly connected to the first high-voltage battery and connectable to a first charging device disposed outside the vehicle to supply electric power to the first high-voltage battery; a second charge port directly connected to the second high-voltage battery and connectable to a second charging device disposed outside the vehicle to supply electric power to the second high-voltage battery; and a controller configured to measure the voltage of the first high-voltage battery-side terminal of the bidirectional converter and the voltage of the second high-voltage battery-side terminal of the bidirectional converter, and determine whether the first charging device is connected to the first high-voltage battery or the second charging device is connected to the second high-voltage battery, the controller being further configured to control the bidirectional converter to supply electric power of the charge port that is electrically connected to either one of the charging devices (210, 230) to one of the first and second high-voltage batteries (110, 130) that is not directly connected to the charging device when the voltage of the high-voltage battery-side terminal of the bidirectional converter is different from the voltage of the low-voltage battery-side terminal of the bidirectional converter, wherein the output voltage of the first charging device is less than the output voltage of the second charging device. a front wheel drive unit for driving a front wheel of a vehicle; a first high-voltage battery configured to supply electric power to the front wheel drive unit; a rear wheel drive unit for driving a rear wheel of the vehicle; a second high-voltage battery configured to supply electric power to the rear wheel drive unit; a bidirectional converter mounted within the vehicle and electrically connected at a first side thereof to the first high-voltage battery and at a second side thereof to the second high-voltage battery; a first charge port directly connected to the first high-voltage battery and connectable to a first charging device disposed outside the vehicle to supply electric power to the first high-voltage battery; a second charge port directly connected to the second high-voltage battery and connectable to a second charging device disposed outside the vehicle to supply electric power to the second high-voltage battery; and a controller configured to measure the voltage of the first high-voltage battery-side terminal of the bidirectional converter and the voltage of the second high-voltage battery-side terminal of the bidirectional converter, and determine whether the first charging device is connected to the first high-voltage battery or the second charging device is connected to the second high-voltage battery, the controller being further configured to control the bidirectional converter to supply electric power of the charge port that is electrically connected to either one of the charging devices (210, 230) to one of the first and second high-voltage batteries (110, 130) that is not directly connected to the charging device when the voltage of the high-voltage battery-side terminal of the bidirectional converter is different from the voltage of the low-voltage battery-side terminal of the bidirectional converter, wherein the output voltage of the first charging device is less than the output voltage of the second charging device.