What does PWM or MPPT mean, in regards to solar charge controllers? – Electus Distribution

Solar charge controllers are equipped with circuits that offer either PWM (Pulse Width Modulation) or MPPT (Maximum Power Point Tracking).

PWM is a cheaper solution, and is applicable only when you have a solar panel whose voltage is matched to your battery voltage, as the PWM controllers can not step-down the panel voltage. E.g. you have a 12v battery connected to a 12v solar panel.

MPPT is a more expensive solution that captures a higher percentage of the solar output, especially on cloudy days, because it can step-down the panel voltage to suit your battery. E.g. you have a 36v panel connected to a 12v battery.