This is because temperature affects the efficiency of a solar panel.
Solar panel temperature controller.
A 100 watt panel at room temperature will be become an 83 watt panel in 110 degrees.
Positive ground controller featuring innovative mppt maximum power point tracking technology with high tracking efficiency up to 99 maximizing the energy from solar panels to charge your system.
Optimize the charging of your deep cycle batteries by the solar panels and prevent electricity stored in the batteries from going through the solar panels when there is no sun.
Solar charge controllers are designed to do two main things within a solar power system.
4 stage charging bulk boost float and equalization and temperature compensation increase your battery life and improve your system s performance.
That being said if your solar panels are regularly exposed to rainy or cold weather then a pwm controller s input voltage ratings will be pulled down as the temperature drops.