Solar charge controllers are required by most solar power systems that involve the use of batteries. They work to regulate the power as it moves from the solar panels to the batteries. A proper charge controller will keep the batteries from being overcharged.
The simplest kind of charge controller functions to monitor the battery voltage Solar Charge Controller and opens the circuit to stop the charging process when voltage reaches a certain level. In early controllers, this was accomplished with the use of a mechanical relay.
Eventually, pulse width modulation (PWM) became the standard for the charge controlling mechanism. This is a technique by which the amount of power transferred to a battery lowers gradually as the battery gets closer to maximum charge. PWM extends battery life even more, as it decreases stress on the battery. It’s also possible to use a PWM controller to keep batteries “floating,” or in a fully charged state, for as long as you like. PWM chargers are more complicated, but they tend to be more durable, as they don’t rely on any breakable mechanical connections.
The latest advancement in solar charge controllers is maximum power point tracking, or MPPT. The central advantage of MPPT controllers is their ability to convert extra voltage into amperage. This feature has a couple of major benefits.
The majority of solar power systems make use of 12 volt batteries, similar to the ones used in cars, but these benefits hold regardless of voltage. Most solar panels produce more voltage than is needed by the batteries. When the extra voltage is converted into amps, the charge voltage stays at an optimal level, while the time it takes to fully charge the batteries is reduced. This way, the solar power system as a whole maintains the highest possible level of efficiency.
An MPPT charge controller will also largely eliminate the amount of power loss that a solar power system experiences. As low-voltage electricity moves along wires, it can experience high levels of loss, reducing the efficiency of the system. The power used by a PWM controller in a system with 12v batteries is in most cases around 18v. With an MPPT controller, the voltage will be significantly higher. This means that MPPT controllers see less loss..
MPPT controllers cost a little more, but they represent a significant improvement. They’re highly recommended because of this.
Preventing reverse-current flow is another ability which certain modern charge controllers possess. Solar panels will stop generating electricity when the sun isn’t out, and the batteries can actually start sending electricity back to them at these times. This power loss can definitely be irritating. At these times, a charge controller will open the circuit, preventing any reverse-current flow back to the solar panels.