A solar charger is a device that harnesses the sun's energy to charge up your devices like the phone, camera, GPS, or even your laptop. Simply put, it converts sunlight into usable electrical energy.
How does a solar charge controller work?
Solar charge controllers typically deploy either pulse width modulation (PWM) or maximum power point tracking (MPPT) technology to regulate and deliver the right amount of current and voltage from PV arrays to run electrical loads and safely charge batteries during the day.
Solar charge controllers ensure the batteries are charged at the proper rate and to the proper level. Without a charge controller, batteries can be damaged by incoming power, and could also leak power back to the solar panels when the sun isn't shining.
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.
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.
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.
Search any solar supply or online marketplace like Amazon and you're bound to turn up dozens of results. The cheapest PWM charge controllers can be had for around $15, and are often rebranded versions of the same design. These lack many features but are relatively reliable for how inexpensive they are.