Everything You Need to Know Before Buying a Solar Charge Controller

Do you want to buy a solar panel system that can absorb more energy from the sunlight, convert it into electrical energy, and power up appliances in commercial, industrial, or home settings? 

If yes, you’ll also require a solar charge controller to function the solar panel system effectively. 

Batteries play an important role in storing excess solar energy in the solar panel system. 

If the power from the solar panels is not kept in control, it might damage the batteries; hence, the load that’s connected to those batteries. This is where a solar panel charge controller is needed.  

Intrigued? Want to know more about solar charge controllers, their technology, and their types? If so, keep reading this post!  

What Is a Solar Charge Controller? 

Well, a solar charge controller is a device that controls the electricity flow and provides balanced energy to the batteries. 

The solar panel charge controller mainly controls the amperage and voltage of the solar array to an appropriate level so that the batteries and the load don’t get damaged. 

Long story short, the primary function of these controllers is to manage the energy flow to and from the batteries. 

Charge controllers ensure that the batteries are charged at a reasonable rate, the appliances don’t get damaged, and that the excess power doesn’t return to the panels and drain the batteries with zero energy. 

For this reason, they are also known as high-powered voltage regulators. 

What Are the Features of a Solar Charge Controller? 

Now that you know the definition, let’s brief you on the key features of a solar charge controller. 

Over the years, this electronic device has undergone many transformations and developed with new features. 

Let’s find out what features you can expect from the most advanced versions. 

  • – Today’s advanced solar panel controller models come with smart sensor technology, Bluetooth, and auto night detection features. 
  • – They also have a timing control facility; hence, they are perfect for street lighting. 
  • – They can recognise voltage seamlessly due to their inbuilt voltage recognition system. 
  • – Auto saving function is also available for the controllers to remember the settings. 
  • – You can change the settings of the controllers and make them work for less or more hours, depending on your needs. 
  • – The controllers also feature a load control facility that controls the electricity provided to the batteries and turns off automatically when the charge is completed. 
  • – Some models come with multi-functioned LCD systems. This allows the users to monitor the functioning of the solar panel charge controller. 
  • – Due to their fault detection feature, they are safe to use and help to know the type of fault and its location. 

Before purchasing a solar charge controller, you can cross-check these features and buy the one with the best available components while keeping your budget and requirements in mind. 

How Is A Solar Charge Controller Connected to a Battery?

Most batteries have a voltage on the terminal of around 12 volts. The two major categories of batteries are 

  • – Lead-acid batteries
  • – Lithium-based batteries

Irrespective of the battery type; the basic connections do not change. They are as follows:

  • – The output of the solar panel controller connects to the battery terminals
  • – The solar panels connect to negative and positive terminals of the solar panel charge controller
  • – A load may also be affixed in parallel with the battery

Oftentimes, solar charge controllers come with extra outputs of USB or separate terminals. However, this connection is for small capacities, such as light. 

What Are the Types of Solar Charge Controllers? 

Solar controllers are of two types: Maximum Power Point Trackers (MPPT) and Pulse Width Modulation (PWM). 

Before any confusion prevails, we’d like to clarify that MPPT and PWM are algorithms, they’re not devices; a solar charge controller is a device. 

When the MPPT algo is embedded in the charge controller, it becomes an MPPT charge controller. When PWM algo is embedded in the charge controller, it becomes a PWM charge controller.

Both these types have their distinct features. Let’s look at them one by one. 

1. Pulse Width Modulation

First things first, PWM charge controllers are outdated models now. They were quite popular during the 90s. Since they were immensely popular once, figuring out their features is quite important. 

  • – PWM controllers are smaller than MPPT. 
  • – They operate below the maximum power voltage. 
  • – Generally, they reduce the battery voltage and align it to the PV modules voltage. 
  • – They manipulate the waveform to modify voltage.

2. Maximum Power Point Trackers

MPPT solar controllers are the newest controllers in the market. They do not reduce the battery voltage; instead, they convert the excess power into amperage. They operate at maximum power voltage and harvest more energy. 

What Should You Buy – PWM or MPPT? 

There’s no denying that PWM controllers once ruled the market. But, that’s not the case anymore. 

Buying MPPT solar charge controllers is, thus, the better option. In many cases, it’s the only option now.

Here are a few things you might want to know about MPPT controllers still:

  • – They’re most suitable for larger systems
  • – They’re extremely efficient
  • – They’re a slight bit heavier to handle
  • – They’re slightly expensive but their efficiency justifies their cost.


Without a solar charge controller, the batteries can get damaged, and the excess energy will get wasted. 

With solar energy being the future of energy supply, the government is organising programmes like ‘Saubhagya Yojana’ and offering subsidies for installations of rooftop solar systems at individual homes and housing societies.

Since MPPT algo maximizes the yield, it’s a smart move to buy an MPPT solar charge controller. 


Q. How can I select the right solar charge controller?

To select the right solar charge controller, check that the controller can handle the energy produced by the solar panels.  

Q. What are the two kinds of solar charge controllers?

The two kinds of solar controllers are pulse width modulation (PWM) and maximum power point tracker (MPPT). 

While PWM is the traditional solar controller that used to be popular in the 90s, MPPT is the modern-day controller with advanced features.

Q. Which one is more efficient – PWM or MPPT?

MPPT is more efficient than PWM as it can work in large systems and produce more energy. 

It is the newest kind of solar panel charge controller available on the market.