Maximum Power Point Tracker

How Does a Solar Charge Controller Work?

The key to understanding the purpose and benefits of solar charge controllers is to learn how it works. In this section, we’ll try to explain things as straightforward as possible, with the hope that you will understand its purpose.

The best way to explain its function is to describe it as a flow regulator.


The electricity that the system receives should not be more than what it can accommodate. It is responsible for managing the potential mismatch.

To add, a solar charge controller also works by preventing battery overcharging. Regardless of the battery that you have, it is built to handle only a specific power. After reaching the latter, it can no longer accommodate additional power. Continuous charging results in increasing voltage. In turn, hydrogen and oxygen molecules will separate. This is a hazard since it will lead to ignition, and consequently, an explosion. The right charge controller prevents this from happening.

More so, you can find solar charge controllers that will work by compensating for any changes in temperature. If the temperature is lower than what is necessary, the controller will help to change the voltage.

Maximum Power Point Tracker

The Two Main Types of Solar Charge Controllers

If you are looking for the best solar charge controller available in the market, one of the most important is to know the two main types. In this section, we’ll have a detailed look at your options.

Pulse Width Modulation (PWM)

A popular choice for those on a budget, PWM acts as an electronic switch that controls the solar panels and battery. While bulk charging, it continuously connects the solar array to the battery. In turn, it pulls down the output voltage so that it will match the battery voltage. When the battery charges, on the other hand, the voltage rises.

While it is cheap, PWM is considered to be an obsolete technology. It is also inefficient, so it isn’t a good choice if you want consistent energy production despite the external conditions, such as the temperature. More so, it can reduce your solar set-up’s voltage.

Maximum Power Point Tracking (MPPT)

Between the two, MPPT is the better option. Unsurprisingly, all of the products we’ll be talking about in this buying guide will belong to this category. It is considered a smart DC to DC converter. It matches the panels with the battery so that the entire system can deliver peak performance. It is considered smart because it monitors the maximum power that the panels can reach. This depends on several external factors, such as shade, temperature, and angle, among others.

One of the advantages of MPPT over PWM is that it can handle higher voltages, making it an excellent choice if you have a high-powered system. This will let you use more solar panels. It can also be up to 95% efficient. This is as against PWM, which can only be up to 65% efficient.

Despite the good things about MPPT solar charge controller, you also need to know some of its drawbacks. They are larger and more expensive. So, this is ideal only for those who have the luxury of space and budget. Nonetheless, the cost is easy to justify because of its exceptional performance and features.

Understanding the Ratings of Solar Charge Controllers

As you try to narrow down the possibilities, one of the most important is to look at the ratings. For the uninitiated, they may seem nothing but numbers. Truth is,
they are important since they are indicative of the overall performance that you can expect from the solar charger controller.

Below are some of the most important things to understand:

• Maximum Input Current: This is related to the maximum output of the solar array that you have. This should be lower that the input limit of the charge controller.

• Maximum PV System Voltage: It is the maximum voltage on the coldest temperature that the PV array allows.

• Operating Input Voltage: Throughout the day, voltages will fluctuate. The controller must have limits that fall under the restrictions of the solar array.

• Maximum Continuous Output Current: This should match the maximum current that a device can generate for charging the battery.

• Nominal Battery System Voltage: The nominal voltage of the battery must match the specifications of the controller you should choose. Most batteries will have a voltage ranging from
12 to 48 VDC. Some can be 60 to 72, but this is common only for those used in industrial applications.


Essential Considerations when Searching for Solar Charger Controllers

While the options are plenty, do not take this as an excuse to decide in haste.

  • Display

The most advanced charge controllers will have a digital display, which is often in the form of LED. This is a good way to easily monitor the functions and performance of the controller. You can see details like battery voltage, state of charge, and the amps from the panels, among other things. Pick a display that is large enough so that you can see it clearly. It is also good if it comes with a backlight, which will be easy for you to see day or night.

  • Data Logging

If you are looking for the best charge controllers, find a product that logs statistics about its performance in a given time. This is a good thing because it allows you to closely monitor the performance of the system. It will give you an idea of how the solar array is doing, and you can execute the necessary solutions when the performance is dismal. This is important for the identification of faults in the system.

  • Weather

External factors like weather will impact your choice of solar charge controller. If you are from a place where weather is unpredictable, you are better off with an MPPT solar charge controller. It has good temperature and voltage compensation. On the other hand, in areas where weather is more consistent, then you should have no problem if you are using a PWM solar charge controller.

  • Appliances to Power

You also need to consider the appliances and devices that you will connect to the system. If you will be using it only for small appliances, you will not have a problem with a controller that features a low voltage disconnect. If you have larger devices, then you will need a more powerful controller. Again, this is one good reason why you should choose MPPT over PWM. The former can handle even large-scale applications.

  • Protection

It is also important to evaluate the safety features that are present in the charge controller. It should have features that protect against over-charging and under-charging. Short-circuiting and over-loading protection are also necessary. These can make you more confident of the system’s optimal functionality while also prolonging service life.

  • Warranty

If you want to have peace of mind, then make sure to find a controller that comes with an extensive warranty coverage. It is common for manufacturers to cover their products for one year. It is better if you find one with a longer warranty. However, make sure to read the terms and conditions so that you will be eligible for the warranty. Do not do anything that violates the terms, or else, the manufacturer will not honor the warranty.

Conclusion for Maximum Power Point Tracker (MPPT)

When talking about solar energy set-up, the panels get the most attention. Some people are unaware that it is a system that includes other parts. Among others, one of the most important is the best solar charge controller, which prevents the battery from overcharging.

If you are buying a solar charge controller, consider our insights above. Focus on our recommendations, and you can hardly go wrong. From construction to functionality, those products are some of the best choices you will ever find.

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