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CLEAN ENERGY REVIEWS. Charge controller and inverter

CLEAN ENERGY REVIEWS. Charge controller and inverter

    clean, energy, reviews, charge, controller


    Reviews and information on the best Solar panels, inverters and batteries from SMA, Fronius, SunPower, SolaX, Q Cells, Trina, Jinko, Selectronic, Tesla Powerwall, ABB. Plus hybrid inverters, battery sizing, Lithium-ion and lead-acid batteries, off-grid and on-grid power systems.

    What is a solar charge controller?

    A solar charge controller, also known as a solar regulator, is basically a solar battery charger connected between the solar panels and battery. Its job is to regulate the battery charging process and ensure the battery is charged correctly, or more importantly, not over-charged. DC-coupled solar charge controllers have been around for decades and are used in almost all small-scale off-grid solar power systems.

    Modern solar charge controllers have advanced features to ensure the battery system is charged precisely and efficiently, plus features like DC load output used for lighting. Generally, most smaller 12V-24V charge controllers up to 30A have DC load terminals and are used for caravans, RVs and small buildings. On the other hand, most larger, more advanced 60A MPPT solar charge controllers do not have load output terminals and are specifically designed for large off-grid power systems with solar arrays and powerful off-grid inverter-chargers.

    Solar charge controllers are rated according to the maximum input voltage (V) and maximum charge current (A). As explained in more detail below, these two ratings determine how many solar panels can be connected to the charge controller. Solar panels are generally connected together in series, known as a string of panels. The more panels connected in series, the higher the string voltage.

    • Current Amp (A) rating = Maximum charging current.
    • Voltage (V) rating = Maximum voltage (Voc) of the solar panel or string of panels.

    MPPT Vs PWM solar charge controllers

    There are two main types of solar charge controllers, PWM and MPPT, with the latter being the primary FOCUS of this article due to the increased charging efficiency, improved performance and other advantages explained below.

    PWM solar charge controllers

    Simple PWM, or ‘pulse width modulation’ solar charge controllers, have a direct connection from the solar array to the battery and use a basic ‘Rapid switch’ to modulate or control the battery charging. The switch (transistor) opens until the battery reaches the absorption charge voltage. Then the switch starts to open and close rapidly (hundreds of times per second) to modulate the current and maintain a constant battery voltage. This works ok, but the problem is the solar panel voltage is pulled down to match the battery voltage. This, in turn, pulls the panel voltage away from its optimum operating voltage (Vmp) and reduces the panel power output and operating efficiency.

    PWM solar charge controllers are a great low-cost option for small 12V systems when one or two solar panels are used, such as simple applications like solar lighting, camping and basic things like USB/phone chargers. However, if more than one panel is needed, they will need to be connected in parallel, not in series (unless the panels are very low voltage and the battery is a higher voltage).

    MPPT solar charge controllers

    MPPT stands for Maximum Power Point Tracker; these are far more advanced than PWM charge controllers and enable the solar panel to operate at its maximum power point, or more precisely, the optimum voltage and current for maximum power output. Using this clever technology, MPPT solar charge controllers can be up to 30% more efficient, depending on the battery and operating voltage (Vmp) of the solar panel. The reasons for the increased efficiency and how to correctly size an MPPT charge controller are explained in detail below.

    As a general guide, MPPT charge controllers should be used on all higher power systems using two or more solar panels in series, or whenever the panel operating voltage (Vmp) is 8V or higher than the battery voltage. see full explanation below.

    What is an MPPT or maximum power point tracker?

    A maximum power point tracker, or MPPT, is basically an efficient DC-to-DC converter used to maximise the power output of a solar system. The first MPPT was invented by a small Australian company called AERL way back in 1985, and this technology is now used in virtually all grid-connect solar inverters and all MPPT solar charge controllers.

    The functioning principle of an MPPT solar charge controller is relatively simple. due to the varying amount of sunlight (irradiance) landing on a solar panel throughout the day, the panel voltage and current continuously vary. In order to generate the most power, an MPPT sweeps through the panel voltage to find the sweet spot or the best combination of voltage and current to produce the maximum power. The MPPT continually tracks and adjusts the PV voltage to generate the most power, no matter what time of day or weather conditions. Using this clever technology, the operating efficiency greatly increases, and the energy generated can be up to 30% more compared to a PWM charge controller.

    PWM Vs MPPT Example

    In the example below, a common 60 cell (24V) solar panel with an operating voltage of 32V (Vmp) is connected to a 12V battery bank using both a PWM and an MPPT charge controller. Using the PWM controller, the panel voltage must drop to match the battery voltage and so the power output is reduced dramatically. With an MPPT charge controller, the panel can operate at its maximum power point and in turn can generate much more power.

    Best MPPT solar charge controllers

    See our detailed review of the best mid-level MPPT solar charge controllers used for small scale off-grid systems up to 40A. click on the summary table below. Also see our review of the most powerful, high-performance MPPT solar charge controllers used for professional large-scale off-grid systems here.

    Battery Voltage options

    Unlike battery inverters, most MPPT solar charge controllers can be used with a range of different battery voltages. For example, most smaller 10A to 30A charge controllers can be used to charge either a 12V or 24V battery, while most larger capacity, or higher input voltage charge controllers, are designed to be used on 24V or 48V battery systems. A select few, such as the Victron 150V range, can even be used on all battery voltages from 12V to 48V. There are also several high voltage solar charge controllers, such as those from AERL and IMARK which can be used on 120V battery banks.

    Besides the current (A) rating, the maximum solar array size that can be connected to a solar charge controller is also limited by the battery voltage. As highlighted in the following diagram, using a 24V battery enables much more solar power to be connected to a 20A solar charge controller compared to a 12V battery.

    Based on Ohm’s law and the power equation, higher battery voltages enable more solar panels to be connected. This is due to the simple formula. Power = Voltage x Current (P=VI). For example 20A x 12.5V = 250W, while 20A x 25V = 500W. Therefore, using a 20A controller with a higher 24V volt battery, as opposed to a 12V battery, will allow double the amount of solar to be connected.

    • 20A MPPT with a 12V battery = 260W max Solar recommended
    • 20A MPPT with a 24V battery = 520W max Solar recommended
    • 20A MPPT with a 48V battery = 1040W max Solar recommended

    Note, oversizing the solar array is allowed by some manufacturers to ensure an MPPT solar charge controller operates at the maximum output charge current, provided the maximum input voltage and current are not exceeded! See more in the oversizing solar section below.

    Solar panel Voltage Explained

    All solar panels have two voltage ratings which are determined under standard test conditions (STC) based on a cell temperature of 25°C. The first is the maximum power voltage (Vmp) which is the operating voltage of the panel. The Vmp will drop significantly at high temperatures and will vary slightly depending on the amount of sunlight. In order for the MPPT to function correctly, the panel operating voltage (Vmp) must always be several volts higher than the battery charge voltage under all conditions, including high temperatures. see more information about voltage drop and temperature below.

    The second is the open-circuit voltage (Voc) which is always higher than the Vmp. The Voc is reached when the panel is in an open-circuit condition, such as when a system is switched off, or when a battery is fully charged, and no more power is needed. The Voc also decreases at higher temperatures, but, more importantly, increases at lower temperatures.

    Battery Voltage Vs Panel Voltage

    For an MPPT charge controller to work correctly under all conditions, the solar panel operating voltage (Vmp), or string voltage (if the panels are connected in series) should be at least 5V to 8V higher than the battery charge (absorption) voltage. For example, most 12V batteries have an absorption voltage of 14 to 15V, so the Vmp should be a minimum of 20V to 23V, taking into account the voltage drop in higher temperatures. Note, on average, the real-world panel operating voltage is around 3V lower than the optimum panel voltage (Vmp). The String Voltage Calculator will help you quickly determine the solar string voltage by using the historical temperature data for your location.

    12V Batteries

    In the case of 12V batteries, the panel voltage drop due to high temperature is generally not a problem since even smaller (12V) solar panels have a Vmp in the 20V to 22V range, which is much higher than the typical 12V battery charge (absorption) voltage of 14V. Also, common 60-cell (24V) solar panels are not a problem as they operate in the 30V to 40V range, which is much higher.

    24V Batteries

    In the case of 24V batteries, there is no issue when a string of 2 or more panels is connected in series, but there is a problem when only one solar panel is connected. Most common (24V) 60-cell solar panels have a Vmp of 32V to 36V. While this is higher than the battery charging voltage of around 28V, the problem occurs on a very hot day when the panel temperature increases and the panel Vmp can drop by up to 6V. This large voltage drop can result in the solar voltage dropping below the battery charge voltage, thus preventing it from fully charging. A way to get around this when using only one panel is to use a larger, higher voltage 72-cell or 96-cell panel.

    48V Batteries

    When charging 48V batteries, the system will need a string of at least 2 panels in series but will perform much better with 3 or more panels in series, depending on the maximum voltage of the charge controller. Since most 48V solar charge controllers have a max voltage (Voc) of 150V, this generally allows a string of 3 panels to be connected in series. The higher voltage 250V charge controllers can have strings of 5 or more panels which is much more efficient on larger solar arrays as it reduces the number of strings in parallel and, in turn, lowers the current.

    Note: Multiple panels connected in series can produce dangerous levels of voltage and must be installed by a qualified electrical professional and meet all local standards and regulations.

    Solar panel voltage Vs Temperature

    The power output of a solar panel can vary significantly depending on the temperature and weather conditions. A solar panel’s power rating (W) is measured under Standard Test Conditions (STC) at a cell temperature of 25°C and an irradiance level of 1000W/m2. However, during sunny weather, solar panels slowly heat up, and the internal cell temperature will generally increase by at least 25°C above the ambient air temperature; this results in increased internal resistance and a reduced voltage (Vmp). The amount of voltage drop is calculated using the voltage temperature co-efficient listed on the solar panel datasheet. Use this Solar Voltage Calculator to determine string voltages at various temperatures.

    Both the Vmp and Voc of a solar panel will decrease during hot sunny weather as the cell temperature increases. During very hot days, with little wind to disperse heat, the panel temperature can rise as high as 80°C when mounted on a dark-coloured rooftop. On the other hand, in cold weather, the operating voltage of the solar panel can increase significantly, up to 5V or even higher in freezing temperatures. Voltage rise must be taken into account as it could result in the Voc of the solar array going above the maximum voltage limit of the solar charge controller and damaging the unit.

    Panel Voltage Vs Cell Temperature graph notes:

    • STC = Standard test conditions. 25°C (77°F)
    • NOCT = Nominal operating cell temperature. 45°C (113°F)
    • (^) High cell temp = Typical cell temperature during hot summer weather. 65°C (149°F)
    • (#) Maximum operating temp = Maximum panel operating temperature during extremely high temperatures mounted on a dark rooftop. 85°C (185°F)

    Voltage increase in cold weather

    Example: A Victron 100/50 MPPT solar charge controller has a maximum solar open-circuit voltage (Voc) of 100V and a maximum charging current of 50 Amps. If you use 2 x 300W solar panels with 46 Voc in series, you have a total of 92V. This seems ok, as it is below the 100V maximum. However, the panel voltage will increase beyond the listed Voc at STC in cold conditions below 25°C cell temperature. The voltage increase is calculated using the solar panel’s voltage temperature coefficient, typically 0.3% for every degree below STC (25°C). As a rough guide, for temperatures down to.10°C, you can generally add 5V to the panel Voc which equates to a Voc of 51V. In this case, you would have a combined Voc of 102V. This is now greater than the max 100V Victron 100/50 input voltage limit and could damage the MPPT and void your warranty.

    Solution: There are two ways to get around this issue:

    • Select a different MPPT solar charge controller with a higher input voltage rating, such as the Victron 150/45 with a 150V input voltage limit.
    • Connect the panels in parallel instead of in series. The maximum voltage will now be 46V 5V = 51 Voc. Note this will only work if you use a 12V or 24V battery system; it’s unsuitable for a 48V system as the voltage is too low. Also note, in parallel the solar input current will double, so the solar cable should be rated accordingly.

    Note: Assuming you are using a 12V battery and 2 x 300W panels, the MPPT charger controller output current will be roughly: 600W / 12V = 50A max. So you should use a 50A MPPT solar charge controller.

    Guide only. Use the new String Voltage Calculator to determine panel voltages accurately.

    Basic guide

    The charge controller Amp (A) rating should be 10 to 20% of the battery Amp/hour (Ah) rating. For example, a 100Ah 12V lead-acid battery will need a 10A to 20A solar charge controller. A 150W to 200W solar panel will be able to generate the 10A charge current needed for a 100Ah battery to reach the adsorption charge voltage provided it is orientated correctly and not shaded. Note: Always refer to the battery manufacturer’s specifications.

    Advanced Guide to off-grid solar systems

    Before selecting an MPPT solar charge controller and purchasing panels, batteries or inverters, you should understand the basics of sizing an off-grid solar power system. The general steps are as follows:

    • Estimate the loads. how much energy you use per day in Ah or Wh
    • Battery capacity. determine the battery size needed in Ah or Wh
    • Solar size. determine how many solar panel/s you need to charge the battery (W)
    • Choose the MPPT Solar Charge Controller/s to suit the system (A)
    • Choose an appropriately sized inverter to suit the load.

    Estimate the loads

    The first step is to determine what loads or appliances you will be running and for how long? This is calculated by. the power rating of the appliance (W) multiplied by the average runtime (hr). Alternatively, use the average current draw (A) multiplied by average runtime (hr).

    • Energy required in Watt hours (Wh) = Power (W) x Time (hrs)
    • Energy required in Amp hours (Ah) = Amps (A) x Time (hrs)

    Once this is calculated for each appliance or device, then the total energy requirement per day can be determined as shown in the attached load table.

    Sizing the Battery

    The total load in Ah or Wh load is used to size the battery. Lead-acid batteries are sized in Ah while lithium batteries are sized in either Wh or Ah. The allowable daily depth of discharge (DOD) is very different for lead-acid and lithium, see more details about lead-acid Vs lithium batteries. In general, lead-acid batteries should not be discharged below 70% SoC (State of Charge) on a daily basis, while Lithium (LFP) batteries can be discharged down to 20% SoC on a daily basis. Note: Lead-acid (AGM or GEL) batteries can be deeply discharged, but this will severely reduce the life of the battery if done regularly.

    For example: If you have a 30Ah daily load, you will need a minimum 100Ah lead-acid battery or a 40Ah lithium battery. However, taking into account poor weather, you will generally require at least two days of autonomy. so this equates to a 200Ah lead-acid battery or an 80Ah lithium. Depending on your application, location, and time of year, you may even require 3 or 4 days of autonomy.

    Sizing the Solar

    The solar size (W) should be large enough to fully charge the battery on a typical sunny day in your location. There are many variables to consider including panel orientation, time of year shading issues. This is actually quite complex, but one way to simplify things it to roughly work out how many watts are required to produce 20% of the battery capacity in Amps. Oversizing the solar array is also allowed by some manufacturers to help overcome some of the losses. Note that you can use our free solar design calculator to help estimate the solar generation for different solar panel tilt angles and orientations.

    Solar sizing Example: Based on the 20% rule, A 12V, 200Ah battery will need up to 40Amps of charge. If we are using a common 250W solar panel, then we can do a basic voltage and current conversion:

    Using the equation (P/V = I) then 250W / 12V battery = 20.8A

    In this case, to achieve a 40A charge we would need at least 2 x 250W panels. Remember there are several loss factors to take into account so slightly oversizing the solar is a common practice. See more about oversizing solar below.

    Solar Charge controller Sizing (A)

    The MPPT solar charge controller size should be roughly matched to the solar size. A simple way to work this out is using the power formula:

    Power (W) = Voltage x Current or (P = VI)

    If we know the total solar power in watts (W) and the battery voltage (V), then to work out the maximum current (I) in Amps we re-arrange this to work out the current. so we use the rearranged formula:

    Current (A) = Power (W) / Voltage or (I = P/V)

    For example: if we have 2 x 200W solar panels and a 12V battery, then the maximum current = 400W/12V = 33Amps. In this example, we could use either a 30A or 35A MPPT solar charge controller.

    Selecting a battery inverter

    Battery inverters are available in a wide range of sizes determined by the inverter’s continuous power rating measured in kW (or kVA). importantly, inverters are designed to operate with only one battery voltage which is typically 12V, 24V or 48V. Note that you cannot use a 24V inverter with a lower 12V or higher 48V battery system. Pro-tip, it’s more efficient to use a higher battery voltage.

    Besides the battery voltage, the next key criteria for selecting a battery inverter are the average continuous AC load (demand) and short-duration peak loads. Due to temperature de-rating in hot environments, the inverter should be sized slightly higher than the load or power demand of the appliances it will be powering. Whether the loads are inductive or resistive is also very important and must be taken into account. Resistive loads such as electric kettles or toasters are very simple to power, while inductive loads like water pumps and compressors put more stress on the inverter. In regards to peak loads, most battery inverters can handle surge loads up to 2 x the continuous rating.

    Inverter sizing example:

    • Average continuous loads = 120W (fridge) 40W (lights) TV (150W) = 310W
    • High or surge loads = 2200W (electric kettle) toaster (800W) = 3000W Considering the above loads, a 2400W inverter (with 4800 peak output) would be adequate for the smaller continuous loads and easily power the short-duration peak loads.

    ATTENTION SOLAR DESIGNERS. Learn more about selecting off-grid inverters and sizing solar systems in our advanced technical off-grid system design guide.

    MPPT Solar Oversizing

    Due to the various losses in a solar system, it is common practice to oversize the solar array to enable the system to generate more power during bad weather and under various conditions, such as high temperatures where power derating can occur. The main loss factors include. poor weather (low irradiation), dust and dirt, shading, poor orientation, and cell temperature de-rating. Learn more about solar panel efficiency and cell temperature de-rating here. These loss factors combined can reduce power output significantly. For example, a 300W solar panel will generally produce 240W to 270W on a hot summer day due to the high-temperature power de-rating. Depending on your location, reduced performance will also occur in winter due to low solar irradiance. For these reasons, oversizing the solar array beyond the manufacturers ‘recommended or nominal value’ will help generate more power in unfavourable conditions.

    Oversizing by 150% (Nominal rating x 1.5) is possible on many professional MPPT solar charge controllers and will not damage the unit. However, many cheaper MPPT charge controllers are not designed to operate at full power for a prolonged amount of time, as this can damage the controller. Therefore, it is essential to check whether the manufacturer allows oversizing. Morningstar and Victron Energy allow oversizing well beyond the nominal values listed on the datasheets as long as you don’t exceed the input voltage and current limits. Victron MPPT controllers have been successfully used with 200% solar oversizing without any issues. However, the higher the oversizing, the longer the controller will operate at full power and the more heat it will generate. Without adequate ventilation, excess heat may result in the controller overheating and derating power or, in a worst-case scenario, complete shutdown or even permanent damage. Therefore always ensure adequate clearance around the controller according to the manufacturer’s specifications, and add fan-forced ventilation if required.

    Warning. you must NEVER exceed the maximum INPUT voltage (Voc) or maximum input current rating of the solar charge controller!

    IMPORTANT. Oversizing solar is only allowed on some MPPT solar charge controllers, such as those from Victron Energy, Morningstar and EPever. Oversizing on other models could void your warranty and result in damage or serious injury to persons or property. always ensure the manufacturer allows oversizing and never exceed the maximum input voltage or current limits.

    about Solar Sizing

    As previously mentioned, all solar charge controllers are limited by the maximum input voltage (V. Volts) and maximum charge current (A – Amps). The maximum voltage determines how many panels can be attached (in series), and the current rating will determine the maximum charge current and, in turn, what size battery can be charged.

    As described in the guide earlier, the solar array should be able to generate close to the charge current of the controller, which should be sized correctly to match the battery. Another example: a 200Ah 12V battery would require a 20A solar charge controller and a 250W solar panel to generate close to 20A. (Using the formula P/V = I, then we have 250W / 12V = 20A).

    As shown above, a 20A Victron 100/20 MPPT solar charge controller together with a 12V battery can be charged with a 290W ‘nominal’ solar panel. Due to the losses described previously, it could also be used with a larger ‘oversized’ 300W to 330W panel. The same 20A Victron charge controller used with a 48V battery can be installed with a much larger solar array with a nominal size of 1160W.

    clean, energy, reviews, charge, controller

    Compared to the Victron MPPT charge controller above, the Rover series from Renogy does not allow solar oversizing. The Rover spec sheet states the ‘Max. Solar input power’ as above (not the nominal input power). Oversizing the Rover series will void the warranty. Below is a simple guide to selecting a solar array to match various size batteries using the Rover series MPPT charge controllers.

    20A Solar Charge Controller. 50Ah to 150Ah battery

    • 20A/100V MPPT. 12V battery = 250W Solar (1 x 260W panels)
    • 20A/100V MPPT. 24V battery = 520W Solar (2 x 260W panels)
    • 40A/100V MPPT. 12V battery = 520W Solar (2 x 260W panels)
    • 40A/100V MPPT. 24V battery = 1040W Solar (4 x 260W panels)

    Remember that only selected manufacturers allow the solar array to be oversized, as long as you do not exceed the charge controller’s max voltage or current rating. always refer to manufacturers’ specifications and guidelines.

    solar charge controller Price guide

    The older, simple PWM, or pulse width modulation, charge controllers are the cheapest type available and cost as little as 40 for a 10A unit. In contrast, the more efficient MPPT charge controllers will cost anywhere from 80 to 2500, depending on the voltage and current (A) rating. All solar charge controllers are sized according to the charge current, which ranges from 10A up to 100A. Cost is directly proportional to the charge current and maximum voltage (Voc), with the higher voltage and current controllers being the most expensive.

    A general guide to the cost of different size solar charge controllers:

    • PWM 100V Solar controllers up to 20A. 40 to 120
    • MPPT 100V Solar controllers up to 20A. 90 to 200
    • MPPT 150V Solar controllers up to 40A. 200 to 400
    • MPPT 150V Solar controllers up to 60A. 400 to 800
    • MPPT 250V Solar controllers up to 80A. 800 to 1200
    • MPPT 300V Solar controllers up to 100A. 900 to 1500
    • MPPT 600V Solar controllers up to 100A. 1600 to 2800

    About the Author

    Jason Svarc is a CEC-accredited off-grid solar power system specialist who has been designing and building off-grid power systems since 2010. During this time, he also taught the stand-alone power systems design course at Swinburne University (Tafe). Living in an off-grid home for over 12 years and having designed, installed and monitored dozens of off-grid systems, he has gained vast experience and knowledge of what is required to build reliable, high-performance off-grid solar systems.


    This is to be used as a guide only. Before making any purchases or undertaking any solar/battery related installations or modifications, you must refer to all manufacturer’s specifications and installation manuals. All work must be done by a qualified person.

    How To connect MPPT Charge Controller To Inverter?

    Solar inverters are a crucial apparatus in your Solar Power which converts the DC power into AC. For a system required to produce output 220V or 110V, consider installing an inverter. An MPPT charge controller is a tracking device that makes the inverter more efficient. MPPT stands for Maximum Power Point Tracking in Solar inverters.

    The photovoltaic modules or PV modules in your Solar panels produce DC power by absorbing the solar energy. Most of the modern appliances at our home or work run on AC, so the inverter runs the electricity through the transformer to convert the DC solar power into AC to run our home. But throughout the day, we don’t get the maximum power out of our system due to weather conditions or variable solar irradiance.

    With MPPT charge controllers installed, you can sit back and relax! MPPT controllers keep our circuit voltage and current at an optimal point to get the maximum power.

    If you wish to get the best out of your system, you should connect an MPPT charge controller to your inverter. But is it okay to connect the MPPT charge controller directly to the inverter? How should we connect the MPPT in our solar system? These questions puzzle our minds.

    Here I tried to give you a complete idea of the MPPT charge controller connection procedure and the do’s and don’t. Read to explore that.

    What are MPPT charge controllers?

    Solar charge controllers basically control the charging and discharging of solar batteries and power output to the load. Maximum Power Point Tracking or MPPT offers us maximized energy extraction from sources with variable energy.

    Solar panels are made of photovoltaic cells or PV cells that generate electrical energy out of solar energy (sun rays, i.e., photons carry energy). But throughout the day, the Sun doesn’t shine equally, which means your solar panels do not produce equal amounts of electricity.

    Also, the solar panel and battery voltage changes as per weather conditions, resulting in deviation in power output efficiency. This problem can be addressed by an MPP (Maximum Power Point) Tracker.

    The MPPT controller constantly monitors and finds the optimal voltage-current array for which you can get maximum power all the time.

    How do they work?

    The most popular solar charger controllers are PWM (Pulse Width Modulation) and MPPT (Maximum Power Point Tracker) charge controllers. MPPT charge controller checks the best power output that your PV system can offer you.

    Then MPPTs adjust the battery voltage and fix the best voltage to get maximum current. MPPTs track your panel voltage and current spontaneously to find the maximum power point. For grid-tied systems, MPPT sets the optimal array voltage-current ratio that gives out maximum power to the inverters.

    In the below situations, MPPTs do their job incredibly good —

    • When the sky is cloudy or at times of lower solar irradiance.
    • When the battery charge is very low.

    If excess voltage is available from the PV, MPPT converts it to the current that is fed to the batteries. The tracking efficiency of MPPT charge controllers is up to 99% which gives a 97% efficient power generation of the whole system.

    Should we connect the MPPT charge controller directly to the inverter?

    Charge controllers need a battery reference to control panel input. You should not connect any charge controller directly to the inverter, and you must connect a battery to your charge controller first. After that, you need to connect the inverter to the battery. A direct connection between the charge controller and inverter can destroy your gadgets.

    MPPTs need a battery connection for a reference voltage to stabilize voltage regulation. MPPT charge controllers help to flow the current efficiently into a depleted battery.

    If we connect an MPPT charge controller directly to the inverter, your system can get damaged, but if not damaged, there will be zero input in the inverter. So connecting MPPTs directly to the inverter is a bad idea! Visual representation of the complete PV system connection

    How to connect an MPPT charge controller?

    You should connect any kind of charge controller to the battery first, and then the inverter needs to be connected to the battery. But at first, check the size of the inverter and the charge controller, if they are compatible. In most cases, a 10A charge controller is too small for inverters.

    • Even before connecting the solar panels, you need to connect the MPPT charge controller to the battery.
    • You can find a male solar panel MC4 connector and a female too. Connect the male solar panel MC4 connector into the adapter kit female connector. And the adapter kit male connector has to be connected with the female solar panel MC4 connector.
    • Connect the positive terminal of the MPPT charge controller to the positive solar panel line. And the negative terminal of the MPPT charge controller to the negative solar panel line. Don’t make any mistakes!
    • Then finally, connect the negative inverter port to the battery’s negative terminal and the positive port to the positive terminal of the solar battery.

    In this way, you can connect an MPPT charge controller correctly to your system without harming any of the equipment. So technically, MPPTs are connected to the inverters via battery junction.

    Can MPPT charge controllers be connected in parallel?

    Yes, MPPT charge controllers can be connected in parallel connection. If your panels might experience constant shading throughout the day, we suggest you connect your controller in parallel. When you go for a parallel connection, the voltage of your panels remains the same, and the current increases.

    clean, energy, reviews, charge, controller

    For example, if you have two 100W panels, each panel can produce about 5.3 amps. Connecting these panels in parallel with the MPPT will produce 200W and 10.58 amps under optimum conditions (Voltage remains the same at 18.9V). A system having high amperage needs a very thick wire to travel long.

    A parallel connection works best if your panels are within 10 feet of your controller. So parallel connection is good for a short distance between panels and MPPT. Also, the parallel system requires branch connectors or combiner boxes as extra equipment.

    Can the MPPT charge controller be connected in series?

    You can connect your MPPT charge controller in series. Most MPPTs are connected in series to increase the voltage and keep the current the same. If the distance between your solar panels and controller is above 20-25 feet, a series connection is recommended for you.

    When panels are connected in series with the controller, the voltage and wattage of the panel add up, and large voltage helps in voltage drop. So that current can run to the controller easily.

    But in series connection, the system’s effectiveness depends on each of the panels. So if any one of the panels is shaded, the whole system will be affected.

    How does an MPPT charge controller differ from an Inverter?

    You need to understand its various parts to get the best results from your solar system. An inverter and an MPPT charge controller are important solar system components, and we use them for different purposes.

    An inverter changes the DC power into AC, whereas the MPPT charge controller enhances the inverter capacity. As the MPPT charge controller helps to deliver maximum power output continuously, it enhances inverter capabilities.

    A charge controller mainly aims to regulate the battery charging and discharging, and its main task is to prevent overcharging and overloading of the battery. Inverters also help in battery charging, but the primary purpose that we need is to transform DC into AC.

    Does an MPPT charge controller always need an Inverter to work?

    Almost every solar system consists of an inverter and charge controller. But if any solar system doesn’t have an inverter but a charge controller, it will work without hesitation!

    But you can run only DC-powered devices in your solar system, and the inverter converts the DC power produced by the panels into AC. Without an inverter, you can run no devices that require AC.

    Mobile phones, laptops, wall clocks, digital cameras even electric vehicles run on DC. The MPPT charge controller will monitor the panel production and give you the best power, and MPPT will help to protect the battery life too.

    But there are many more electronic gadgets we need on a daily basis, and they run on AC. So not having an inverter seems impractical and incomplete.

    Can an Inverter work without any charge controller?

    Yes! An inverter works as it should be, even without a charge controller. Many inverters don’t require any charge controller. For grid-tied solar systems, you don’t even need a battery. Your system runs fine without a battery.

    The excess power produced by your system goes back to the power grid, and you can draw energy from the grid whenever you need it. So, no need to buy and install a solar battery.

    Grid-tied solars are quite famous as they are easy to install and cheaper than off-grid solar systems as you don’t need to buy a battery or any kind of charge controller.

    Charge controllers FOCUS on the battery’s charging cycle; hence you need one if you have batteries in your solar system. Using batteries and inverters without a charge controller is not what Smart people do!

    Can your Solar system work without an Inverter?

    As long as you can run your house or work on DC power, you don’t need an inverter. As I said earlier, PV panels produce DC power from the sunlight. Any devices that run on DC can be connected directly to the panels, and there is no need for an inverter to change the DC power into AC.

    So you can use your solar system without installing an inverter, but that will put a limit on your usage.

    Does your Solar system need a Charge Controller all time?

    Charge controllers are not a must-buy for your solar system. A solar system can run finely without a charge controller or even a battery. A grid-tied solar system feeds its excess energy to the utility grid and also draws energy from the grid if needed. They work just fine without a battery until there is a power outage.

    For an off-grid system, it is mandatory to have a battery and a charge controller to get a 24×7 steady power supply. Charge controllers are a necessary safeguard for your battery. Otherwise, excess current can flow into the batteries and damage them.

    But theoretically, you can run an off-grid system without a battery or a charge controller. But you will get electricity only during the sunny hours, and with the Sundown, there will be no electricity.

    Some well-known MPPT charge controllers with their prices:

    • Victron Energy SmartSolar MPPT 100V: SmartSolar MPPT charge controllers are hugely liked over the BlueSolar MPPTs. The basic difference between SmartSolar and BlueSolar is that the SmartSolar MPPTs have built-in Bluetooth. It helps you to monitor and configure them easily through smartphone apps. This model comes in varieties of ampere levels. A 15A charge controller costs 137.70. A 20A, 30A and 50A charge controller cost 156.00, 226.09 and 314.00 respectively. They are quite pricey but provide you with high efficiency.
    • Victron Energy SmartSolar MPPT MC4 250V 60amp 12/24/36/48V: It comes with a price of 638.35 and provides you with overall good performance as per customer review. Easy to install, but this product doesn’t have a display.


    We all are looking forward to the wholesome use of renewable energy sources. rapidly and conveniently. Solar energy comes first to our mind as our very own Sun is an enormous source of energy.

    Also, solar power is getting noticeably common and cheap. Knowledge about different solar system parts can only ease your work as an owner. Knowing how to connect a device correctly in the system can help you set up the system quickly and efficiently.

    Hello readers, I am a Physics and Mathematics enthusiast concerned about the growing environmental distress. I am a content writer here at LivelyWatt intending to build awareness about ecological problems and also trying to inspire every reader for green living. Together we can make the Earth a better place to live.

    Pure sine wave Inverter Combined charger MPPT solar controller 230V/50Hz, 800-4000W

    HSP series MAGNIZON POWER inverter/charger with duel operational modes with built in MPPT solar charge controller minimizes the hassles of solar installation especially in hybrid environments. Large LCD display with functional keys to select various parameters and displays real time information along with operational schemes. Day time will be supported through solar panels and night time or rainy days will be with batteries and Utility power with intelligent microprocessor based automatic switching. Reliable transformer less IGBT based design and frequency controlled powers very much compatible to all varieties of loads: resistive/inductive loads such as refrigerators, motors, pumps, compressors and laser printers as well as electronic loads like TV’s, Computers, power tool and battery chargers. Smart micro controller based 3-stage built in charging system properly charge and maintain battery bank in the obscene of solar power or rainy days. The charge rate is selectable so you can use a variety of battery sizes and types to fit your back up time requirements.


    • 12V/24V/48V DC or 230V AC input; 230V, 50 Hz output (hardwired)
    • 800/1600/2400/3200/4000 watts continuous output with double boost capacity.
    • Microprocessor controlled Smart volume design
    • Built in power management software and communication cable with the unit
    • Dry contact communications system for remote management SCADA applications
    • Built in MPPT solar charge controller Utility based charger
    • Duel Operational Mode UPS/ Solar Inverter Mode
    • Robust design for Hybrid configuration Pure sine wave output
    • High Efficiency Using Line-Interactive Circuit Topology(Full Bridge Topology)
    • Quiet, high efficiency operation, high surge capacity and low idle current
    • CE Safety
    • Selectable input voltage range and frequency according to city power in your country
    • Charging current is settable according to your battery type
    • Configurable AC/Solar input priority via LCD setting
    • Compatible to mains voltage or generator power
    • Auto restart while AC is recovering
    • Overload, over temperature and short circuit protection
    • Smart charging system optimizes battery performance
    • Cold start function
    • Parallel capability up to 4 units which available on HSP4048SW-LCD HSP5048SW-LCD only


    • Well designed for hybrid applications where solar energy systems connected along with grid or generator sets.
    • Versatile inverter/charger with pure sine wave system with seamless transfer switching serves as an automotive inverter for RVs, trucks, standalone alternative power source with high end back up times with various battery technologies(VRLA, GEL, Deep cycle, Ni-Cd and many more)
    • Perfectly suitable for On-grid, Off-grid and Hybrid applications.
    • Telecom and ATM applications.
    • Small PV plants for houses/villas and small offices.
    • Remote closets and small computer room applications.
    • Mining, fluid flow management, Oil gas applications.






    90V AC /- 7V (Appliances mode)

    100V AC /- 7V (Appliances mode)

    Line Mode: Circuit Breaker

    Battery Mode: Electronic Circuits

    5sec @150% load; 10sec@110~150% load

    Charge Mode Specs

    Solar Charging Mode Specs

    General Specs

    5% to 95% Relative Humidity (non-condensing)

    RS232 Cable along with monitoring software included

    Yes. Ability to monitor Power OFF/On, LOW DC, Battery voltage, charge status etc


    HSP series MAGNIZON POWER inverter/charger with duel operational modes with built in MPPT solar charge controller minimizes the hassles of solar installation especially in hybrid environments. Large LCD display with functional keys to select various parameters and displays real time information along with operational schemes. Day time will be supported through solar panels and night time or rainy days will be with batteries and Utility power with intelligent microprocessor based automatic switching. Reliable transformer less IGBT based design and frequency controlled powers very much compatible to all varieties of loads: resistive/inductive loads such as refrigerators, motors, pumps, compressors and laser printers as well as electronic loads like TV’s, Computers, power tool and battery chargers. Smart micro controller based 3-stage built in charging system properly charge and maintain battery bank in the obscene of solar power or rainy days. The charge rate is selectable so you can use a variety of battery sizes and types to fit your back up time requirements.

    What is a Solar Charge Controller

    A solar charge controller manages the power going into the battery bank from the solar array. It ensures that the deep cycle batteries are not overcharged during the day, and that the power doesn’t run backwards to the solar panels overnight and drain the batteries. Some charge controllers are available with additional capabilities, like lighting and load control, but managing the power is its primary job.

    A solar charge controller is available in two different technologies, PWM and MPPT. How they perform in a system is very different from each other. An MPPT charge controller is more expensive than a PWM charge controller, and it is often worth it to pay the extra money.

    PWM Solar Charge Controller

    A PWM solar charge controller stands for “Pulse Width Modulation”. These operate by making a connection directly from the solar array to the battery bank. During bulk charging, when there is a continuous connection from the array to the battery bank, the array output voltage is ‘pulled down’ to the battery voltage. As the battery charges, the voltage of the battery rises, so the voltage output of the solar panel rises as well, using more of the solar power as it charges. As a result, you need to make sure you match the nominal voltage of the solar array with the voltage of the battery bank. Note that when we refer to a 12V solar panel, that means a panel that is designed to work with a 12V battery. The actual voltage of a 12V solar panel, when connected to a load, is close to 18 Vmp (Volts at maximum power). This is because a higher voltage source is required to charge a battery. If the battery and solar panel both started at the same voltage, the battery would not charge.

    A 12V solar panel can charge a 12V battery. A 24V solar panel or solar array (two 12V panels wired in series) is needed for a 24V battery bank, and 48V array is needed for 48V bank. If you try to charge a 12V battery with a 24V solar panel, you will be throwing over half of the panel’s power away. If you try to charge a 24V battery bank with a 12V solar panel, you will be throwing away 100% of the panel’s potential, and may actually drain the battery as well.

    MPPT Solar Charge Controller

    An MPPT solar charge controller stands for “Maximum Power Point Tracking”. It will measure the Vmp voltage of the panel, and down-converts the PV voltage to the battery voltage. Because power into the charge controller equals power out of the charge controller, when the voltage is dropped to match the battery bank, the current is raised, so you are using more of the available power from the panel. You can use a higher voltage solar array than battery, like the 60 cell nominal 20V grid-tie solar panels that are more readily available. With a 20V solar panel, you can charge a 12V battery bank, or two in series can charge up to a 24V battery bank, and three in series can charge up to a 48V battery bank. This opens up a whole wide range of solar panels that now can be used for your off-grid solar system.

    The Key Features of a Solar Charge Controller are:

    • Multistage charging of battery bank. changes the amount of power set to the batteries based on its charge level, for healthier batteries.
    • Reverse current protection. stops the solar panels from draining the batteries at night when there is no power coming from the solar panels.
    • Low voltage disconnect. turns off attached load when battery is low and turns it back on when the battery is charged back up.
    • Lighting control. turns attached light on and off based on dusk and dawn. Many controllers are configurable, allowing settings for a few hours or all night, or somewhere in between.
    • Display- may show voltage of battery bank, state of charge, amps coming in from solar panel.

    Shop for a solar charge controller among these great brands, now!

    • MPPT
    • PWM
  • MPPT
  • PWM
  • MPPT
  • PWM
  • MPPT
  • PWM
  • MPPT
  • PWM
  • MPPT
  • MPPT
  • Or, call us today at 877-878-4060 to see which solar charge controller is best for your application!

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