Solar Controllers, MPPT or PWM

MPPT (Maximum Power Point Tracking) and PWM (Pulse Width Modulation) are two different types of solar charge controllers used to regulate the amount of charge coming from solar panels to batteries.

PWM controllers work by switching the solar panel's output on and off, creating a square wave that charges the battery. The controller monitors the battery voltage and adjusts the amount of time the panels are switched on to maintain a constant voltage. However, PWM controllers are not very efficient in converting the solar energy to battery power and can result in up to a 30% power loss.

On the other hand, MPPT controllers use a more advanced technology to track the maximum power point of the solar panel array and adjust the output accordingly to ensure maximum power transfer. MPPT controllers can convert a higher percentage of the solar panel's power into battery power, up to 98%, making them more efficient than PWM controllers.

Overall, MPPT controllers are more expensive than PWM controllers, but they can make up for their cost with their higher efficiency, especially in larger solar panel installations.