The control electronics and battery system of solar cars are generally complex and expensive. For example, it is necessary to convert the fairly low and definitely fluctuating voltage at the terminals of the solar panels into a higher stable voltage.

We can do it easier.

We use an electrical circuit where a solar panel, an electric motor and supercapacitors connected in series are connected to a rail.

As long as the voltage at the terminals of the pair of supercapacitors is lower than the voltage required to rotate the electric motor, the car stands still and the supercapacitors sail. As the voltage increases, at some point it reaches a value that causes the electric motor to rotate. If you turn off the solar panel from here on, as it happens when you go from light to darkness, the electric motor will run for a while on the support of the electrical energy stored in the supercapacitors.

Simple!

In the video, you can see the entire procedure, from building the circuit necessary for charging to demonstrating an electric motor that works in the dark with the help of supercapacitors.

Such a test is possible only if the voltage at the terminals of the solar panel not connected to the circuit is 5-6 volts, which means using a powerful incandescent lamp in sunny weather or in room conditions.

The time required for charging can be predicted by measuring the strength of the current generated by the solar panel in specific lighting conditions and using the corresponding calculator.