PWM charge controllers represent a more foundational and cost-effective solution in solar energy systems. Their operation is based on the principle of pulse width modulation, a technique that involves the regulation of the energy flow to the batteries by adjusting the duration of the charging pulses.
How do solar charge controllers work?
We'll examine each function individually below. Modern solar charge controllers work by detecting and monitoring the battery's voltage level and closely regulating the flow of current from the panels to the battery.
This is called “pulse width modulation” (PWM). Both methods work well when set properly for your type of battery. PWM solar charge controllers hold the voltage more constant. If a PWM controller has two-stage regulation, it will first hold the voltage to a safe maximum for the battery to reach full charge.
What are the different types of solar charge controllers?
Inverter.com offers you two kinds of solar charge controllers, Maximum Power Point Tracking (MPPT) controllers and Pulse Width Modulation (PWM) controllers. In addition, the all-in-one unit - solar inverter with MPPT charge controller is also available for off-grid solar systems.
How to choose a solar charge controller?
A charge controller must be capable of handling this power output without being overloaded. Therefore, it's essential to tally the combined wattage of all solar panels in the system and choose a controller with a corresponding or higher wattage rating.
Overcharging can lead to excessive gassing, heat generation, and even dangerous situations like battery explosions in severe cases. By moderating the charge, solar charge controllers ensure that the batteries are charged efficiently and safely, promoting longer battery life and maintaining the integrity of the solar power system.
The diagram below shows the working principle of the most basic solar charge and discharge controller. The system consists of a PV module, battery, controller circuit, and load. Switch 1 and Switch 2 are the charging switch and the discharging switch, respectively.