PWM vs. MPPT Solar Controllers

Solar controllers regulate power from panels to batteries, preventing overcharging. The two main types—PWM and MPPT—differ in efficiency and application.

Typical PWM charge controller

PWM Controllers

PWM (Pulse Width Modulation) controllers act as a switch, reducing panel voltage to match battery voltage around 13v, leading to energy losses. Since voltage is pulled down, panels rarely operate at peak efficiency of 18v.

Best for: Small solar systems in warm climates (40°C+).

Viictron MPPT charge controller

MPPT Controllers

MPPT (Maximum Power Point Tracking) controllers continuously adjust voltage to extract maximum power. By preventing direct linkage between panel and battery, they minimize voltage drop and can increase energy harvest by 30% or more, especially in cooler conditions.

Best for: Larger systems, colder/cloudy climates, or shaded environments.

Conclusion

PWM controllers are budget-friendly for small setups in hot climates. MPPT controllers optimize power output, support larger arrays, and perform better in varied weather.

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