A solar charge controller is a type of regulator that transfers the energy from solar panels to the batteries and load. The charge controller is used to charge the batteries with the electrical energy obtained from solar energy. The charging voltage is regulated to suit the batteries and the batteries are protected by reducing the current when the batteries are about to be full.
A solar charge controller is a type of regulator that transfers the energy from solar panels to the batteries and load. The charge controller is used to charge the batteries with the electrical energy obtained from solar energy. The charging voltage is regulated to suit the batteries and the batteries are protected by reducing the current when the batteries are about to be full.
Solar panels are usually sold in 12 V and this type of solar panel has an output voltage in the range of 16-20 V. In order to charge the batteries, a voltage in the range of 14-14.5 V is usually needed. Therefore, solar panels cannot be connected directly to batteries. The energy obtained from solar panels must be brought to the appropriate voltage and current levels and transmitted to the batteries.
Batteries are usually the most expensive part of a solar energy system. The charge controller protects the batteries from both over-charging and over-discharging, extending their lifetime.
If a battery is completely discharged, its lifetime is severely shortened. Therefore, load control is extremely important in solar energy systems. The charge control circuit protects the batteries from over-discharge by cutting the energy to the load below a certain voltage.
Overcharging any type of battery can cause irreparable damage. Overcharging lead-acid batteries boils the liquid inside, causing excessive gassing. This can damage the battery plates and cause the battery to swell or explode.
There are two different types of charge controllers available for solar systems.
The first is PWM (pulse width modulation) controllers, which are widely used throughout the industry. PWM controllers basically act as a switch between the solar panel and the battery. The switch is controlled by quickly opening and closing the charging current. The controller constantly checks the state of the batteries and determines how wide the pulses to be sent. When the battery is full, the pulses are short and sent every few seconds. When the battery is discharged, the pulses are very long or the controller is always on.
The second is MPTT (Maximum power point tracking) charge controllers, which are more advanced and more complex. MPTT controllers measure the voltage of the panel and reduce it to a voltage suitable for the battery. Current and voltage values are continuously optimized to achieve maximum power. In this way, it can work more efficiently than a PWM controller.
MPPT technology is more expensive than PWM technology. It may not be the right choice to choose MPPT charge controllers in every application. System components and application requirements should be evaluated as a whole.
The solar charge controller has two connection terminals for the solar panel, load and battery. Each system component should be connected by paying attention to the positive and negative poles. When making system connections, battery cables should be connected first. The thickness and connector type of the cables to be used should be determined according to the maximum operating current.
The charge control unit may have an LCD display or only a small indicator LED. Although the settings of each device are different, the basic structure is very similar. The operating mode (day, night, continuous) and duration (hours) of the system can be set using the buttons on the device. Advanced devices also have features such as battery type adjustment, battery voltage monitoring, low and high voltage limit setting. For all these, the user manual provided by the manufacturer should be reviewed.
