What do you need to look for in a solar charge controller?

A solar charge controller can be defined as a charge regulator that keeps the batteries away from overcharging. It is responsible for monitoring the voltage and current coming from solar panels and going to the battery.

The primary responsibility of a solar charge controller is to ensure that deep cycle batteries are not overcharged. It also checks that the power does not run back to the solar panels during the night and damage the solar panels.

Storing electricity to do useful work later requires batteries to be connected to a solar PV system. After a battery is added, a charge controller becomes one of the essential solar system components.

Some of the primary functions performed by a solar charge controller have been listed below:

1. Stops Reverse Current at Night

At night the batteries may pass a small amount of current in the reverse direction, resulting in a small discharge from the battery, which can damage the solar panel. To prevent this damage, a solar charge controller helps in stopping reverse current during night time.

2. Prevents Overcharging

Once a battery is charged, it cannot store any extra incoming energy. Preventing overcharge is a simple process in which the flow of the energy is reduced to the battery when the battery reaches a specific voltage.

Solar charge controllers come in a wide range of prices, power ratings, and features.

Following are the two types of charge controllers that are available in the Indian market:

• Pulse Width modulation (PWM)

PWM Charge controllers function by making a direct connection from the solar array to the battery bank. During bulk charging, there is a continuous connection between the array and the battery bank. The output voltage is pulled down to the battery voltage. As the battery charges, the voltage of the battery rises; therefore, the voltage of the solar panel increases.

• Maximum Power Point Tracking (MPPT)

MPPT controllers are much more sophisticated. They can easily adjust the input voltage and current of the PV array to find the optimum operating voltage that will help in generating the most power at a given time. You can use MPPT controllers with higher voltage PV arrays above nominal voltage.

Key Factors Responsible for the Selection of a Charge Controller

MPPT technology is more expensive when compared to a PWM. For a well-sized system, MPPT and PWM controllers will do a perfect job of keeping the batteries charged. Opting for a pulse width modulation or maximum power point tracking will depend upon one’s location and application.

It is a prerequisite to opt for the right solar charge controller in terms of size and features. For remote-based systems, reliability and performance are important aspects that you need to take into consideration.

Small charge controllers come with the added advantage of being fanless, which means they can get rid of heat by passive cooling. By removing the fan, you can benefit in the following ways:

1. High Reliability

Fans come with moving parts, usually the only component with moving parts on a charge controller. By eliminating the fan, you remove the most common point of failure.

2. Longer Life

Fans pull in dirt and dust, which can clog the charge controller’s insides and shorten its life.

3. Greater Efficiency

Fans need electricity to operate, and the electricity comes from the solar electricity flowing from the panels.

Whether you choose a large or a smaller solar charge controller, choose wisely according to your budget and needs. Apart from the application, budget, and location, the most important step is spending time and care in selecting the right charge controller. Trusted brands such as Luminous offer an extensive range of charge controllers with unique features like an inbuilt low voltage disconnect, automatic battery selection, thereby offering 98% efficiency.