MPPT Charge Controller Intro

MPPT Charge controller is a technology that is specifically made to work with virtually all the photovoltaic. 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 which they are able to. On the other hand, it’s not the mechanical tracking technology which physically moves the modules towards the direction of the sun to convert more solar energy to electrical energy. At MPPT solar charge controller is a smart electronic device which looks at the power output of the solar array which is feeding power into the charge controller and looks at the battery collection which is needing charging and matched the voltage and current to utilize the utmost output of the solar array.

What is mppt charge controller

The MPPT controller refers to the “Maximum Power Point Tracking” solar charge controller, which is an upgraded product of the traditional solar panel charge controller. The MPPT solar charge controller can detect the solar panel voltage and current in real time and constantly tracking for the maximum power (P=U*I) so that the system always charges the battery with maximum power.

What is Maximum Power Point Tracking

The Maximum Power Point Tracking (MPPT) system is an electrical system that enables the photovoltaic panel to output more power by adjusting the working state of the electrical module. The DC power generated by the solar panel can be effectively stored in the battery. It can effectively meet the needs of living and industrial electricity in remote areas and tourist areas that cannot be covered by conventional power grids and does not cause environmental pollution.

The MPPT controller detects the solar panel’s generated power voltage in real time and tracks the highest voltage and current value (VI), then the system can charge the battery with maximum power output. It is the brain of the photovoltaic system used in solar photovoltaic systems to coordinate the work of solar panels, batteries and loads.

since the solar collection affected by the sunlight and external factors such as surrounding factors, the output power changes, when the sunlight is strong, the power converted more. the MPPT Solar Charge controller is designed to make full use of the solar array to keep it stay in the Peak conversion. in the case of same sunlight, the output power by an MPPT Solar Controller is higher than a PWM Charge Controller.

How MPPT Charge Controller Works

The MPPT control is generally completed by a DC/DC converter circuit. The photovoltaic cell array is connected to the load through a DC/DC circuit, and the maximum power tracking device continuously detects the current-voltage variation of the photovoltaic array, And Automatic adjust the PWM drive signal duty cycle of DC/DC Converter according to the variation.

For linear circuits, when the load resistance is equal to the internal resistance of the power supply, the power supply has the maximum power output. Although photovoltaic cells and DC/DC converter circuits are strong-nonlinearity, However, in a very short time, it can be considered as a linear circuit. As long as the equivalent resistance of the DC-DC converter circuit is adjusted so that it is always equal to the internal resistance of the photovoltaic cell, the maximum output of the photovoltaic cell can be realized, and the Max power point of the photovoltaic array is realized.

How to Size MPPT Solar Charge Controller

As technology, Goes fast Nowadays, the MPPT solar controllers Types are also various, When we want to choose the right mppt solar controller, we have to pay attention to 2 aspects: the current of the solar panel and the voltage of the solar panel.

Solar Panels Voltage

As Per the Solar panels, we need to pay attention to the working voltage and short-circuit voltage, working voltages normally as 18V, 36V and so on. There is also a short-circuit voltage. If it is 18V, the short-circuit voltage of the solar panel should be 22V, and the 36V the short-circuit voltage should be 42V. We need to choose the right controller according to the working voltage of the solar panels. usually, when you buy the solar panels, you will have the parameters information.

Solar Panels Current

The size of the solar controller we often name is actually how much current the solar controller handles (that is, the maximum charging current). on the market, generally, a solar controller will have 10A, 20A or 30A Sizes, and some high power controller also can handle will have 50A, 60A Current. Even More Greater. 80A Solar Controller and 100A Solar Controller are also common, When selecting the controller, please noted that the discharge current of the solar panel cannot exceed this value, otherwise the controller will be damaged. So, when choosing a controller, we recommend that if the solar panel current is 6A, we should choose a 10A charge controller.

The Solar Panels input voltage of the MPPT solar controller is generally about 0~150V, and the input voltage of the PWM solar controller is generally 0~55V. As long as the voltage is under these voltage values, the right mppt controller is easy to find. in case of special business, if these input voltages are higher than the rated values, it’s also easy to find a solar charge controller manufacturer to order one.

What is the best mppt charge controller

the best mppt solar controller is the one which most suitable for your solar project, it requires fit your batteries. and you need to know all the details of your PV system, such as the input and output power, maximum battery current, nominal system voltage (12V, 24V,36V,48V,60V,100V,150V Even 200V). When considering which mppt controller to choice, referring to the mppt controller calculation guide above.

MPPT Charge Controller vs PWM: Advantages

As you know, in order to charge the battery, the output voltage of the solar panel must be higher than the current voltage of the battery. If the input voltage is lower than the voltage of the battery, the output current will be close to zero. Moreover, the output of the solar panel is not fixed but varies with various conditions such as radiation intensity, ambient temperature, etc., and whether the solar panel can work at the maximum value of the IV curve or not, based on the designer’s Level and ability.

The operating parameters of the traditional solar charging controller are set unchanged. The parameter mode (constant voltage or constant current) is used to transfer the solar panel energy. It won’t change even the surrounding environment changes. but The natural environment of the sun’s radiation, the surrounding temperature and humidity are changing all the time; therefore, if the energy of the solar panels is converted in a fixed way, which will cause the battery inadequate charge. On the other hand, when the weather is good and has good sunlight, the solar powers cannot be fully utilized, it’s kind of a waste.

We know that in an independent photovoltaic solar system, the cost of solar panels and batteries accounts for 80%-90% of the total system budget, and the controller only accounts for 5%-10%. If the design is reasonable, 5% budget solar controller can optimize the system in the best.

In a practical case, you can see the benefits of the MPPT controller more clearly: in a system that uses a conventional PWM charge controller with a 1000W solar panel, if PWM controller is replaced by an MPPT controller, the same load, the same battery, you only need to install 700W solar panels, it’s enough to meet the power demand of all electrical equipment. according to the current market price of solar panels $2/W, the cost of solar panels in the system can be directly reduced to $650. In such cases, in larger systems, the cost savings can be greater, including the cost of purchasing the panels, cables, and more.

In addition, there are still many amorphous silicon solar panels on the market. One trait of this type of panel is that the open circuit voltage is high and the current is small. In practical applications, the traditional PWM controller, including the constant current controller, can only convert the panel energy with low efficiency, which will cause the battery inadequate charge or Undervoltage. which shortens the service life of batteries. not to mention the solar panels energy waste. The maximum power point tracking controller can offset the defects in these practical applications, thereby improving system performance.

The difference between MPPT solar controller and PMW controller

The main difference between MPPT controller and PWM controller is in three aspects.

Charge Method Difference

The charging method is different, as the PWM is charged in a three-stage charging mode. MPPT is the maximum power tracking technology, and the relative charging efficiency can be increased to about 30%.

Charge Voltage Difference

When using an MPPT solar controller to charging a low-voltage battery by a high-voltage solar panel, the Charge efficiency will have a big difference with the PWM Controller under the same condition. If the voltage of the solar panels and the battery are the same, for example, both are 12V, then the difference between the practical PWM and the MPPT controller won’t much.

Solar Power Difference

If the power of the solar panel is small, it is better to take a PWM charge controller. if the power of the solar panel is large, the MPPT solar controller is a better choice. usually, the mppt solar controller is much expensive then a PWM controller, if the power of the solar panel is small, it is a little of waste money to take the MPPT controller.

Features of MPPT Charge Controller

MPPT is Usually used in the off-grid solar power generation systems, the energy converted from solar panels is a very valuable resource. If using a traditional PWM controller, as the disadvantage of low conversion rate, a lot of energy is wasted. If using an MPPT Charge Controller instead, the solar conversion rate can be increased a lot, the MPPT solar controller is obviously a better choice when the budget is rich.

Highlights of MPPT Charge Controller

1. High energy conversion efficiency, up to 99%;

2. Support all types of solar panels, such as monocrystalline silicon panels, polycrystalline silicon panels, amorphous silicon panels, etc.;

3, rich load working mode: such as time control, pure light control, light control + time control, manual, debug mode, long open mode;

4, good circuit protection functions, including PV reverse connection protection, PV over-current protection, battery reverse connection protection, battery over-voltage protection, battery over-discharge protection, load over-current protection, load short-circuit protection, etc.

7, support serial communication functions (Extra WiFi, Bluetooth Control and Monitor Devices)

8, can support various types of batteries, such as lead-acid batteries, lithium iron phosphate batteries, etc.;

9, support a variety of battery voltage, such as 12V, 24V, 36V, 48V, 110V and so on.

3 Stage Charging Mode of MPPT Charge Controller

MPPT Limiting Charge

when the initial charge stage starts, the system detected the battery voltages drop in a low value and can be charged, then the MPPT charge starts working to convert and transfer the PV Output Power to the Battery. when the sunlight is strong, the output power of the PV array will be greatly increased. and the charge current hit the threshold value, then the MPPT Charge Stoped and turn into constant charge mode. when the sunlight decreases, the constant charge turns into the MPPT Charge. by this switch way. the battery will be fully charged and the voltage will increase to the Saturation voltage (Ur), then the battery turns into the constant charge stage. as the charge mode auto-switch between the MPPT Charge and Constant Charge, the solar energy can be fully utilized to charge the battery in an efficient and quick way.

Constant Voltage Limiting Charge

At this stage, the charging voltage value is always Ur, and the charging current gradually decreases as the electrochemical reaction in the battery. When the charging current drops to about 0.01 C, the constant voltage charging is terminated and the floating charging phase is entered. the charge current also has limited to protect the battery at this stage.

Floating Charge

The charge voltage (Uf) in the floating charge mode is a little lower than the constant charge. the main purpose of this charge mode is to compensate for the self-losing energy of the battery. at this stage, the battery charge has completed.

Benefits of MPPT Solar Charge Controller

when MPPT controller used, the charging efficiency can be improved by 30%, i.e. the same solar panels output, the MPPT controller can generate a charging current of 1.3 times than before, so the battery can be charged faster.

The working principle of the MPPT controller: The MPPT controller will track the maximum power point in the solar panel in real time, and the solar panel can output the maximum efficiency. The higher the voltage, the more power can be output through the maximum power tracking, thus improving the charging efficiency. In theory, use MPPT controller solar power system will increase efficiency by 50% than the traditional ways, but in actual, according to zhcsolar testing, due to environmental factor affection and energy losses, the final efficiency can be increased by 20% – 30%.

The Importance of MPPT Solar Charge Controller

• When you look at the many solar panels out there and begin to see their results, you’ll see that the range of voltages from low to high and have the variation of the voltage in normal operating parameters. A usual solar panel is made to work in excess of 18 volts. Storage batteries are made to a range of predefined voltage that is based on the structure of the battery. 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 at the same time provides them the security from getting undercharged or overcharged. You connect the regulator straight to the battery and then to the solar module. A high-quality MPPT solar charge controller works out and analyzes the voltage at which the module could generate utmost power as for its capability. Effectiveness and efficiency of most of the MPPT solar charge controller are between 93% and 96%. This kind of solar charge controller is valuable in cold weather and on cloudy days when there’s almost no sunshine. This is the time when more power is needed to charge the battery in order to keep the SOC level.
• An MPPT solar charge controller could be a remarkable combination with a grid-tied solar module. Another remarkable benefit of the MPPT solar charge controller is that you save lots of time in the cable and wiring expenses that means which 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 as well as automatic load reconnection.
• Electronic Security: Overcharging security, deep discharging security, reverse polarity protection from the module side as well as from the side of the battery. Reverse polarity security from the internal fuse, short circuit security as well as overvoltage security at module input. Also, you need to ensure that there’s open circuit security without battery, over temperature as well as overload security and even battery overvoltage shutdown.

MPPT Charge Controller Circuit Diagram

MPPT Solar Charge Controller Negative Ground vs Postive Ground

In Simple Word, all vehicles have a NEGATIVE ground system. so when you choosing the MPPT Solar Charge Controller for RV and Autos, Remeber to Choose the Negative Grounding Charge Controller. Here I will explain Why.

All vehicles use the battery as the storage of electric energy. All the input and output of electric energy 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 Vehicles is designed to use as the circuit of the negative pole. This means that the vehicle’s steel frame or chassis is directly connected to the negative side of the battery via the negative battery cable.

MPPT Charge Controller Price

The price of the MPPT solar charge controller is usually 3-5 times then the PWM controller which in the same size (amp). Generally, the price difference of the small amp is not as big as the big amps. The price difference between mppt controller and PWM controller jumped from 30 amps. Mppt controller price range from $70 to $1000 is common on the market. an mppt unit over $1000 is not unusual especially when is a big unit. according to Comparison Shopping Engine – PriceGrabber, the most expensive 60A MPPT Solar Charge Controller is priced at $1,000.68 by MidNite Solar Classic Lite 60A Controller.

In the long run, the mppt controller has a higher return on investment not matter for the home off-grid system or for commercial purposes. we strongly recommend taking an mppt controller for your power system.

Best MPPT Solar Charge Controller on the Market

ZHCSolar MPPT Charge Controller Comparison

ZHCSolar MPPT Solar Charge Controller has 30 Amp, 40A, 50 Amp, 60 Amp, 80 Amp, 100 Amp Version for Off-Grid Solar Panel System. The table shows the comparison parameter of battery voltage, rated charge current, nominal PV power, maximum PV short circuit current and maximum PV open circuit voltage for references.

Victron MPPT Charge Controller Comparison

We have arranged the different Victron MPPT solar charge controllers in a table below to allow easy selection of the right charge controller for your needs. The table shows the comparison parameter of battery voltage, rated charge current, nominal PV power, maximum PV short circuit current and maximum PV open circuit voltage for references.

Renogy mppt charge Controller Comparison

Conclusion

In general, the MPPT controller tracks the maximum power point in the solar panel in real time to maximize the effectiveness of the solar panel. The higher the voltage, the more power can be output through the maximum power tracking, thus improving the charging efficiency. In this sense, the MPPT solar charge and discharge controller is going to eventually replace the traditional PWM solar controller.