A solar charge controller (also known as a regulator) is identical to a traditional battery charger. Its function is to manage the solar charging process to ensure that the battery is effectively filled or, more critically, not overloaded. While solar charge controllers come in a wide variety of budgets, supply voltage, and functionalities, there are two major types: PWM and MPPT solar charge controller units. PWM variants are less complicated, utilizing a switch between the solar plant system and the storage devices. We will dive deeper into the difference later in this article.
Various battery kinds are supported, much like with any standard battery charger. Normally, the absorption and float voltages are selectable. In addition, the time periods and tail current are often adjustable. DC-connected solar charge controllers have been employed in virtually all limited-scale off-grid solar power plants for years. They are ideal for lithium-iron-phosphate batteries. Once the batteries are fully charged, the controller will remain at the predetermined float of roughly 13.6V for the rest of the day.
The Basics of a Solar Charge Controller
Not sure what a solar charge controller actually does? Let’s have a quick look at the video below:
In summary, a solar charge controller distributes energy from the solar panels to both the power and the battery systems. When the battery bank is pretty much full, the controller reduces the current flow to preserve the needed voltage to stay at the fully charged level and preserve the battery’s life.
“Protects” is the essential term here. The solar charge controller protects the battery by controlling the flow. Because batteries are usually the most costly component of a system, a solar charge controller will safeguard them from the harmful effects of both overcharging and undercharging.
Modern solar charge controllers may also measure temperature and regulate battery charging accordingly to enhance performance. This is known as temperature adjustment. It charges to a greater voltage in cold conditions and a lower voltage in warmer conditions.
The solar charge controller is usually viewed as the heart and brain of the whole solar power plant. It guarantees long-term battery life under all operational situations and controls crucial loads.
MPPT and PWM Solar Charge Controllers
A PWM solar charge controller’s switch may open and shut quickly, allowing it to pulse the power flowing from a photovoltaic panel to cut down the charge flow as the batteries become fully charged. Since PWM controllers simply use a switch, the array voltage in operation will be equivalent to the battery voltage.
PWM solar charge controllers are an excellent value for compact 12V setups with one or fewer solar cells. One issue arises when the solar panel voltage is reduced to fit the battery voltage. This causes the panel voltage to deviate from its optimal working voltage, reducing the system’s efficiency.
MPPT controllers, on the other hand, are more advanced. They may change and track the input voltage to achieve the right operating voltage that will make the greatest electricity at a particular time.
MPPT solar charge controllers can be approximately 30% more productive using innovative technology, depending on the solar array voltage installed. MPPT controllers can also be employed with PV arrays with greater voltages. This enables the adoption of many other solar PV panels, which may be less expensive and have much more optimal productivity.
MPPT and PWM controllers will both perform a good job of keeping the battery charged in an appropriately sized system. The decision between PWM and MPPT is really dependent on the application and environment.
The solar voltage must decrease to suit the battery voltage when using a PWM controller. As a result, the output current is drastically reduced. With an MPPT solar charge controller, the panel may function at its maximum power output, generating significantly more electricity.