EV Car's battery voltage and charging with solar panel
What really matters is the energy capacity of the batteries measured in kWh. The base Nissan Leaf has a 30 kWh battery.

With 3 x 200 W solar panels in optimum orientation and illumination would generate 0.6 kW. With 100% output and 100% inverter efficiency (both of which are impossible) you would charge the battery in 30 / 0.6 = 50 hours of continuous sunlight. Of course, since the Earth rotates this will take at least 100 hours.