For the battery of your vehicle to charge, the car needs not be moving. Rather, it is the movement of the car alternator that charges your battery. As the engine of the car is running, the car doesn't need to be moved; this engine movement will cause the alternator to move, thereby charging the car battery. It is to be noted that when the car is not moving while the alternator is moving, the power generated from the alternator will be small, which will charge the battery slowly. The alternator will move faster and give more power to the battery of the car when the car is driving.