A long-term measurement shows the typical charge and discharge behavior following day–night cycles. Even under cloudy conditions, the supercapacitors are charged close to their maximum voltage levels.

In this example, the ESP32-C3 operates in continuous deep sleep mode. Between February 19 and February 20, snowfall occurred in Bratislava, covering the solar panel. As a result, the supercapacitors could not be recharged for three days.

Despite this, the voltage did not drop below 4.1 V, demonstrating the system’s robustness under unfavorable environmental conditions.