Solar Charge Controller Definitive Guide

Solar Charge Controller Intro

The solar charge controller is also known as the charge and discharge controller. It is used in the solar power system to control the solar cell array to charge the battery and maintain the battery to supply power to the solar inverter load.

It regulates battery charge and discharge voltage.

The solar charge controller controls the power output of the PV solar cell module and the battery to the load in accordance with the electrical demand of the load, which is the core control part of the entire photovoltaic power supply system.

The Basics of Solar Charge Controllers

Solar charge controllers are primarily designed to do two essential things within the solar power system: prevent electricity from the batteries from going through the solar panels when there’s no sun, and optimize battery charging through the solar panels.

There are many solar charge controllers on the market.

Most have various additional features, including the ability to automatically turn DC powered loads on or off, provide monitoring of voltage and remaining battery amp-hours, and connect to a home data network for efficient remote monitoring.

How to size a charge controller

Voltage and amperage are the specifications for solar charge controllers. To support the voltage of your solar array and then output to the voltage of the battery bank, you need the right solar controller. You will also need to make sure that the capacity of your solar charge controller is large enough to handle the current coming from your solar panel array.

To estimate how many amps the controller will need, you need to take the wattage of your solar panels and divide it by the voltage of the battery bank.

Multiplying the array’s short-circuit current by 1.56 is another way to size a charge controller. Just be sure that the solar charge controller of your choice can handle at least that many amps.

Key features of solar charge controllers

Solar charge controllers provide multi-stage charging of battery banks. This means that they change the amount of power set to the batteries according to their state of charge, for more valuable and healthier batteries.

When there is no sun or power from the solar panels, they prevent the solar panels from discharging.

They will also turn off any connected load when the battery is running low, and then turn it back on when the battery is recharged.

There are also a wide variety of solar charge controllers available on the market today. There are 40A and 30A solar charge controllers. They safely control your power source and protect your batteries from overcharging. They also provide essential protection from getting reversed.

In addition, some solar charge controllers offer low-voltage disconnect, adjustable set points for the control voltage, overload measurement, and overload protection. They also significantly improve battery charging. This makes them an essential component of any solar power system.

What are the types of solar charge controllers?

MPPT solar charge controllers. The latest innovation in solar systems today is the Maximum Power Point Tracking (MPPT) solar charge controller. This controller is able to determine the optimum current and operating voltage of the solar panel array and match it to the battery bank. The result is fifteen to thirty percent more power from your solar array.

The different types of solar charge controllers include the following types:

PWM solar charge controllers. Pulse Width Modulated (PWM) solar charge controllers are the traditional type of controller. They are the most common, widely used in many solar panel applications, and the most affordable. It is a passive controller technology that uses solid state gates and switches to produce a constant DC output from a varying DC input.

Let’s compare the mppt charge controller and the pwm charge controller one on one:

MPPT Solar Charge Controller

MPPT solar charge controller is a technology specifically made to work with virtually all photovoltaics. Certainly, it’s for the solar unit wherein module voltages are higher than the battery voltages.

It’s an electronic system that assists the solar module produces all the power it can. On the other hand, it’s not the mechanical tracking technology that physically moves the modules towards the sun’s direction to convert more solar energy to electrical energy.

An MPPT solar charge controller is a smart electronic device that looks at the power output of the solar array, feeding power into the charge controller and looks at the battery collection that needs charging and matches the voltage and current to utilize the maximum output of the solar array.

The Importance of MPPT Solar Charge Controller

  • Storage batteries are made to a range of predefined voltage based on the battery’s structure. When you look at the many solar panels out there and see their results, you’ll see the range of voltages from low to high and vary the voltage in normal operating parameters. A usual solar panel is made to work more than 18 volts. A lot is made to work at 12 volts.
  • Check out the works or functions of a standard PV regulator. It tracks the battery charging and provides them with security from getting undercharged or overcharged. You connect the regulator straight to the battery and the solar module.
  • A high-quality MPPT solar charge controller works out and analyzes the voltage at which the module could generate the maximum power for its capability.
  • The effectiveness and efficiency of most of the MPPT solar charge controllers are between 93% and 96%. This solar charge controller is valuable in cold weather, cloudy days, and almost no sunshine. This is when more power is needed to charge the battery to keep the SOC level.
  • An MPPT solar charge controller could be a remarkable combination with a grid-tied solar module. Another amazing benefit of the MPPT solar charge controller is that you save lots of time on cable and wiring expenses which means a smaller gauge cabling or wiring could be utilized.
  • While selecting an MPPT solar charge controller, you have to ensure that these essential features are on hand:
  • Voltage and Current Regulation, Pulse with Modulation or PWM control, current compensation load disconnection, temperature compensation, and automatic load reconnection.

Electronic Security

Overcharging security, deep discharging security, and reverse polarity protection from the module side and from the side of the battery. Reverse polarity security from the internal fuse, short circuit security, and overvoltage security at module input.

Also, you need to ensure that there’s open circuit security without battery, over temperature, overload security, and even battery overvoltage shutdown.

PWM Solar Charge Controller

What is PWM Solar Charge Controller and Its Incredible Benefits?

Pulse Width Modulation is the most effective way to attain constant voltage battery charging by switching the power devices of the solar system controller. This new and innovative method of solar battery charging provides some of the impressive benefits of pulse width modulation pulsing, which include:

  • Increase the battery’s charge acceptance dramatically.
  • Ability to maintain high average battery capacity compared to the on-off regulated state-of-charge levels, which are typically fifty-five to sixty percent.
  • Adjust automatically for battery ageing.
  • Reduce heating and gassing of battery.

In addition to these benefits, using an innovative PWM Solar Charge Controller over the old technology reduces the solar system’s cost and battery disposal issues. It also increases the solar system’s reliability and reduces load disconnects. It also provides the opportunity to reduce the battery’s size to lower the system’s cost.

If you need more power whenever you want it for less money, this product is the right one to consider. It will help you obtain twenty to thirty percent more energy from solar panels for charging. Stop wasting the power from your solar system when the battery is only fifty percent changed using PWM Solar Charge Controller.

PWM Solar Charge Controller is also the most common, cost-efficient and easiest to deploy solar charge controller technology. Commonly mistakenly referred to as DC to DC converters, this controller is a switch similar to a power supply that matches the source voltage to the load voltage.

Pulse Width Modulation is quite simple and has been around for many decades. One of its incredible advantages is that PWM Solar Charge Controllers won’t take advantage of the panels’ full capacity under most conditions.

According to Ohm’s law, the current is inversely proportional to voltage, but PWM solar controllers won’t do anything with the current. Once the high voltage from the solar panel is converted to a usable form of 12 volts, the current out will be the same or lesser than the current in.

PWM Solar Charge Controllers are cost-efficient and the most common choice for amateur radio operators. Their price and simplicity make the energy tradeoff a very acceptable compromise.

The Technology of the PWM Solar Charge Controller

With the growing number of residential, commercial and even industrial industries going solar these days, solar systems have become even more popular than ever before.

With this, solar photovoltaic battery charge controller technology has continued to evolve. The most innovative technology is PWM charging, which has become highly popular.

Charging a solar system’s battery is a daunting and unique challenge. Before, on-off regulations were used to limit battery outgassing once a solar panel generated excess energy.

However, as solar systems developed, it became even clearer how much such devices interfered with the charging process. With this challenge, PWM solar charge controller has become the solution.

Types of Solar Chargers Controllers and Where to Buy

Knowing the proper use of solar charge controllers when relying greatly on solar energy in your daily life is essential. Solar charge controllers come in all sizes, shapes, and types.

You will find MPPT solar charge controllers, PWM solar charge controllers, 40A solar charge controllers, and 30A solar charge controllers.

Easy to set up, a solar charge controller is required in virtually every solar power panel which uses batteries. A lot of solar panels controlled out there come with either digital displays or simple Led. At this point, you will also find a solar charger controller that comes with a computer interface for better tracking, monitoring, and control.

How Does a Solar Panel Charges Controller Works?

The main job of a solar panel charge controller is to regulate the energy passing from the solar panel to the battery. They help properly keep your solar power unit’s batteries by preventing them from being under or overcharged.

As a result, providing long-life batteries. The current passing in the solar charge controllers charges the batteries used in various household items.

Also, this current could be passed to the investors for changing direct current or DC to alternating current or AC. At night or if the solar modules are not producing any power or energy, energy could flow backwards from the batteries to the solar modules, which drains the batteries.

A solar charger controller will assure you that this will not happen. Once solar energy isn’t passing from the solar panels to the circuit, it cuts off the solar panels from the batteries and stops the reverse stream of current.

Where to Find the Best and Right Solar Charge Controller?

Choosing a high-quality solar charger controller will make the most of the life of these batteries in your solar system. Buying a cheap unit will lead to shorter battery life and a greater long-term expense as you will have to replace your battery sooner.

Then, unless you like the same thing to take place, you will need to replace the solar charge controller. You will find many solar charge controllers online. On the other hand, looking for a high-quality solar charger regulator matters.

Avoid buying a reasonable charger controller because it might hamper the life of your battery and, at the same time, enhance overall costs in due course.

For your peace of mind, do not compromise on superiority and quality. is the leading provider of high-quality solar charge controllers.

They have a wide selection of solar charge controllers, such as MPPT solar charge controllers, PWM solar charge controllers, 40A solar charge controllers as well as 30A solar charge controllers.

All these can be obtained for a fraction of the cost, especially today, wherein the company offers a huge discount on all their solar charger products.

Solar charge controller Grounding

If you hook up the solar charge controller with your RV, you need a negative ground controller.

In Simple Words, all vehicles have a NEGATIVE ground system. So when you choose the MPPT Solar Charge Controller for RV and Autos, Remember to Choose the Negative Grounding Charge Controller. Here I will explain Why.

All vehicles use the battery for the storage of electric energy. All the input and output of electric power must pass through the battery. Since the battery is direct current (DC), the positive and negative poles become equally important. This is the basic principle of the negative ground.

When the Vehicles Exworks, the Body of the Vehicle is designed to use as the circuit of the negative pole. This means the vehicle’s steel frame or chassis is directly connected to the negative side of the battery via the negative battery cable.

solar charge controller connection

Complete the wiring as the Following steps or check this wiring guide.

1. Most solar controllers are 6 wires Terminal. This is easy to judge which wire to connect, There are 3 groups, and each has 2 mounting holes for positive and negative poles.

Usually, the solar panel cord is the first group of wires, then the battery, and finally the load, which connect the positive pole at first, then the negative pole at last.

2. Some solar controllers are 5 wires terminals. In this case, The solar panel and the battery share the positive pole, and the negative pole is separated. The load uses a separate terminal.

When wiring, just connect the positive pole of the panels and the battery together and the left wiring as usual.

3. 4 wires terminal, usually solar panels, batteries, and the load share the positive pole. When your wiring, just connect the three positive poles together. The negative poles are wired as usual.

4. connect sequences, connect the battery first, then the solar panel, and finally the load. This wiring method prevents the controller from misjudging the voltage of the battery.


What is the best solar charge controller?

The best solar controller is the one most suitable for your solar project. It requires fitting your batteries. And you need to know all the details of your PV system, such as the input and output power, maximum battery current, and nominal system voltage (12V, 24V,36V,48V,60V,100V,150V Even 200V).

When considering which mppt controller to choose, refer to the mppt controller calculation guide above.

How to select a solar charge controller

What size solar charge controller do I need?

There are many types of solar controllers on the market. What size solar charge controller do I need? This is always the question that confuses solar users. When sizing the solar charge controller, it can be considered from the following aspects:

The voltage of the solar panel

Generally, 18V solar panels typically use a 12V controller, 36V solar panels use a 24V controller, and 72V solar panels use a 48V controller.

solar panel current

The solar panel current calculation method is to divide the solar panels’ power by the solar panel’s highest charging voltage.

For example. a 12V/200W solar panel. The maximum charging voltage is 18V, and the current of the solar panel is 12A. When we size the solar charge controller, it Usually gives a 30% to 50% margin, then the best choice for us to make is a 15A controller, a 20A controller is the best.

the type of battery

nowadays, many types of batteries are on the market, such as maintenance-free lead-acid batteries, colloid batteries, ternary lithium batteries, lithium iron phosphate batteries, etc.

The highest charging voltage and working voltage of various batteries are different. So when we select the solar charge controller, we need to check the parameter of the battery first.

Usually, those parameters are printed with the battery body and user guides.

High-quality solar controllers are equipped with lightning protection, high voltage, low voltage, overload protection and temperature compensation to ensure the normal operation of the entire system.

At the same time, you can also know the electricity generated and the amount of electricity used daily according to the controller statistics function.

The service life of a solar charge controller is generally 5 to 8 years. Therefore, using solar panels to charge the battery directly is not recommended, which will affect the battery life.

Solar controllers are not expensive, even scrapped batteries, but it is worth the money.

Why do I need a solar panel charge controller?

To save costs, some users believe that a solar controller is an unnecessary component. Can a solar panel charge the battery without a solar controller?

The answer is yes, but the problem is that overcharging can result in a scrapped battery without the solar controller’s regulation.

When a solar panel charges a battery, we usually add a key component called a solar controller. What does the solar controller do? It is to protect the battery from charging and discharging.

If there is no such controller. The battery is easy to bump and even explode.

how to wire up a solar charge controller

Following the guide, Solar Panel Charge Controller Wiring Diagram to Wiring and set up the solar charge controller, battery bank and solar panels in the solar power system.

Simple sequence: first, connect the battery, set the operating mode of the load via the solar charge controller, connect the solar panel, and connect the load to the last.

When disconnecting the solar power system, disconnect in the reverse order.

Solar Panel Charge Controller Wiring Diagram 

How many solar panels can you hook to one charge controller?

When you buy a solar charge controller, you will find this information in the user manual. Usually, the maximum power of PV indicates full panels you can hook to the charge controller.

Types of Solar Charge Controller and applications

There are many types of solar controllers on the market, such as solar street light controllers, solar panel charge controllers, RV solar charge controllers, marine solar charge controllers, etc.

Each of these controllers has its own function and Features. In practice, as applications are different, we must be clear about what the controller is applied to the application. Here are 3 mainstream types of solar charge controllers:

Off-grid solar panel charge controller

The solar panel charge controller is mainly used in the off-grid solar power system, Generally installed indoors. Used primarily for household power generation, outposts, base stations, and other power supply systems. Main applications: solar battery charging, DC load output, LCD display, manual switch.

The main types are normal, economical, 12V/24V self-type, MPPT type, App Control type, high power type, and 48V type.

solar street light controller

Mainly used for solar street lights, installed in the pole or lamp holder. This kind of street light controller usually is a Fully potted metal casing. The solar street light controller can automatically control the ON/OFF and lighting time according to the actual requirements.

The solar street light controller usually has the following types: normal output (battery voltage), boost type, buck type, timer type, dual timer period, and multiple time type.

RV solar Charge Controller

RV solar charge controllers can also be divided by MPPT and PWM types. And dual battery solar chargers also can be found on the market when you want to charge 2 batteries simultaneously on the RV.

A dual-battery solar charger can charge 2 batteries simultaneously, generally used in the RV solar power system to charge the RV start and main batteries. Usually does not have a load output function.

How to Choose the good solar charge controller

4 factors to be aware of when buying the solar charge controller

1. Function: the function of the solar charge controller. We all know that the main function of the solar charge controller is charge and discharge regulation. Still, usually, besides the charge regulation, the charge controller also has extra functions based on the manufacturer and design.

2. Quality: first look at the shell material. There are 3 types of shell material: ABS, aluminium alloy, and ABS + aluminium alloy, Solar controllers shell use ABS and ABS+ aluminium alloy are more common because the cost of the all-aluminium alloy is expensive, then the price of the solar controller is high accordingly.

3. Terminals: Check the terminal and buttons and shake the solar controller. If it sounds like something dropped, the controller is not firmly assembled.

4. After-sales: some customers must research the product before buying the solar controller. After purchasing the controller, it needs more experience to install and wire it. Thus, Guaranteed after-sales service and support are also very important.

Solar Charge Controller Working Parameters

There are two kinds of operating parameters shown by the solar controller. One is displayed by LED light, that is, several LED lights flash to indicate the controller’s current state.

The second type is the LCD display. The LCD display is more user-friendly, and all the working parameters are digitized and graphically displayed. It can be easily read. If you want to know the operating parameters of your controller more clearly and accurately, it is recommended to use the LCD display type controller.

The LCD display mainly shows the operating parameters:

1, the charging voltage of the solar panel

2, solar panel charging current

3, the amount of power of solar panels (aka how much electricity is outputted)

4, the capacity of the battery

5, the battery voltage

6, battery temperature

7, the load current

8, the amount of power used

There are many manufacturers of solar controllers on the market, and the models are different. Reading the manual carefully and following instructions to set the controller parameters is recommended. The technical parameters displayed will be other.

The values on the LCD display help the user understand the operational status of the entire solar system. LCD display Features are easy to understand, clear and intuitive, which is also the scientific basis for users to judge whether the solar system works normally or not.

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