Morningstar SunGuard

SunGuard uses Pulse Width Modulation (PWM) technology to maximize charging efficiency. PWM is the most effective means to achieve constant voltage battery charging by switching the solar system controller's power devices. When in PWM regulation, the current from the solar array tapers according to the battery's condition and recharging needs. SunGuard's PWM charging, compared to On-Off solar regulators, typically allows 30% more solar energy into the battery per day. Also, the average battery State-of-Charge is 90 - 95%, which is much more than 50 - 60% for On-Off regulators.