Looking to buy mppt charge controller? What is an MPPT Charge Controller?This section covers the theory and operation of “Maximum Power Point Tracking” as used in solar electric charge controllers. Let us now look at the Mppt Solar Charge Controller Price below.
An MPPT, or maximum power point tracker is an electronic DC to DC converter that optimizes the match between the solar array (PV panels), and the battery bank or utility grid. To put it simply, they convert a higher voltage DC output from solar panels (and a few wind generators) down to the lower voltage needed to charge batteries.
(These are sometimes called “power point trackers” for short – not to be confused with PANEL trackers, which are a solar panel mount that follows, or tracks, the sun).
So what do you mean by “optimize”?
Solar cells are neat things. Unfortunately, they are not very smart. Neither are batteries – in fact, batteries are downright stupid. Most PV panels are built to put out a nominal 12 volts. The catch is “nominal”. In actual fact, almost all “12-volt” solar panels are designed to put out from 16 to 18 volts. The problem is that a nominal 12-volt battery is pretty close to an actual 12 volts – 10.5 to 12.7 volts, depending on state of charge. Under charge, most batteries want from around 13.2 to 14.4 volts to fully charge – quite a bit different than what most panels are designed to put out.
OK, so now we have this neat 130-watt solar panel. Catch #1 is that it is rated at 130 watts at a particular voltage and current. The Kyocera KC-130 is rated at 7.39 amps at 17.6 volts. (7.39 amps times 17.6 volts = 130 watts).
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Why 130 Watts does NOT equal 130 watts
Where did my Watts go?
So what happens when you hook up this 130-watt panel to your battery through a regular charge controller?
Unfortunately, what happens is not 130 watts.
Your panel puts out 7.4 amps. Your battery is sitting at 12 volts under charge: 7.4 amps times 12 volts = 88.8 watts. You lost over 41 watts – but you paid for 130. That 41 watts are not going anywhere, it just is not being produced because there is a poor match between the panel and the battery. With a very low battery, say 10.5 volts, it’s even worse – you could be losing as much as 35% (11 volts x 7.4 amps = 81.4 watts. You lost about 48 watts. [technical note: that lost power is actually getting converted into heat. It’s not actually missing, it’s just not usable by the charge controller.]
One solution you might think of – why not just make panels so that they put out 14 volts or so to match the battery?
Catch #22a is that the panel is rated at 130 watts at full sunlight at a particular temperature (STC – or standard test conditions). If the temperature of the solar panel is high, you don’t get 17.4 volts. At the temperatures seen in many hot climate areas, you might get under 16 volts. If you started with a 15-volt panel (like some of the so-called “self-regulating” panels), you are in trouble, as you won’t have enough voltage to put a charge into the battery. Solar panels have to have enough leeway built in to perform under the worst of conditions. The panel will just sit there looking dumb, and your batteries will get even stupider than usual.
Nobody likes a stupid battery.
What is Maximum Power Point Tracking?
There is some confusion about the term “tracking”:
Panel tracking – this is where the panels are on a mount that follows the sun. The most common are the Zomeworks. These optimize output by following the sun across the sky for maximum sunlight. These typically give you about a 15% increase in winter and up to a 35% increase in summer.
This is just the opposite of the seasonal variation for MPPT controllers. Since panel temperatures are much lower in winter, they put out more power. And winter is usually when you need the most power from your solar panels due to shorter days.
Maximum Power Point Tracking is electronic tracking – usually digital. The charge controller looks at the output of the panels and compares it to the battery voltage. It then figures out what is the best power that the panel can put out to charge the battery. It takes this and converts it to best voltage to get maximum AMPS into the battery. (Remember, it is Amps into the battery that counts). Most modern MPPT’s are around 93-97% efficient in the conversion. You typically get a 20 to 45% power gain in winter and 10-15% in summer. Actual gain can vary widely depending weather, temperature, battery state of charge, and other factors.
Grid tie systems are becoming more popular as the price of solar drops and electric rates go up. There are several brands of grid-tie only (that is, no battery) inverters available. All of these have built in MPPT. Efficiency is around 94% to 97% for the MPPT conversion on those.
How Maximum Power Point Tracking works
Here is where the optimization or maximum power point tracking comes in. Assume your battery is low, at 12 volts. An MPPT takes that 17.6 volts at 7.4 amps and converts it down so that what the battery gets is now 10.8 amps at 12 volts. Now you still have almost 130 watts, and everyone is happy.
Ideally, for 100% power conversion you would get around 11.3 amps at 11.5 volts, but you have to feed the battery a higher voltage to force the amps in. And this is a simplified explanation – in actual fact, the output of the MPPT charge controller might vary continually to adjust for getting the maximum amps into the battery.
On the left is a screenshot from the Maui Solar Software “PV-Design Pro” computer program (click on the picture for full-size image). If you look at the green line, you will see that it has a sharp peak at the upper right – that represents the maximum power point. What an MPPT controller does is “look” for that exact point, then does the voltage/current conversion to change it to exactly what the battery needs. In real life, that peak moves around continuously with changes in light conditions and weather.
An MPPT tracks the maximum power point, which is going to be different from the STC (Standard Test Conditions) rating under almost all situations. Under very cold conditions a 120-watt panel is actually capable of putting over 130+ watts because the power output goes up as panel temperature goes down – but if you don’t have some way of tracking that power point, you are going to lose it. On the other hand under very hot conditions, the power drops – you lose power as the temperature goes up. That is why you get less gain in summer.
MPPT’s are most effective under these conditions:
Winter, and/or cloudy or hazy days – when the extra power is needed the most.
- Cold weather – solar panels work better at cold temperatures, but without an MPPT you are losing most of that. Cold weather is most likely in winter – the time when sun hours are low and you need the power to recharge batteries the most.
- Low battery charge – the lower the state of charge in your battery, the more current an MPPT puts into them – another time when the extra power is needed the most. You can have both of these conditions at the same time.
- Long wire runs – If you are charging a 12-volt battery, and your panels are 100 feet away, the voltage drop and power loss can be considerable unless you use very large wire. That can be very expensive. But if you have four 12 volt panels wired in series for 48 volts, the power loss is much less, and the controller will convert that high voltage to 12 volts at the battery. That also means that if you have a high voltage panel setup feeding the controller, you can use much smaller wire.
Ok, so now back to the original question – What is an MPPT?
How a Maximum Power Point Tracker Works:
The Power Point Tracker is a high-frequency DC to DC converter. They take the DC input from the solar panels, change it to high-frequency AC, and convert it back down to a different DC voltage and current to exactly match the panels to the batteries. MPPT’s operate at very high audio frequencies, usually in the 20-80 kHz range. The advantage of high-frequency circuits is that they can be designed with very high-efficiency transformers and small components. The design of high-frequency circuits can be very tricky because of the problems with portions of the circuit “broadcasting” just like a radio transmitter causing radio and TV interference. Noise isolation and suppression becomes very important.
There are a few non-digital (that is, linear) MPPT’s charge controls around. These are much easier and cheaper to build and design than the digital ones. They do improve efficiency somewhat, but overall the efficiency can vary a lot – and we have seen a few lose their “tracking point” and actually get worse. That can happen occasionally if a cloud passed over the panel – the linear circuit searches for the next best point but then gets too far out on the deep end to find it again when the sun comes out. Thankfully, not many of these around anymore.
The power point tracker (and all DC to DC converters) operates by taking the DC input current, changing it to AC, running through a transformer (usually a toroid, a doughnut looking transformer), and then rectifying it back to DC, followed by the output regulator. In most DC to DC converters, this is strictly an electronic process – no real smarts are involved except for some regulation of the output voltage. Charge controllers for solar panels need a lot more smarts as light and temperature conditions vary continuously all day long, and battery voltage changes.
Mppt Solar Charge Controller Price
All recent models of digital MPPT controllers available are microprocessor controlled. They know when to adjust the output that it is being sent to the battery, and they actually shut down for a few microseconds and “look” at the solar panel and battery and make any needed adjustments. Although not really new (the Australian company AERL had some as early as 1985), it has been only recently that electronic microprocessors have become cheap enough to be cost-effective in smaller systems (less than 1 KW of the panel). MPPT charge controls are now manufactured by several companies, such as Outback Power, Xantrex XW-SCC, Blue Sky Energy, Apollo Solar, Midnite Solar, Morningstar and a few others
EPEVER MPPT Charge Controller
- Type: MPPT
- Battery voltage: 12-24V
- Max input voltage: 100V
- Max current output: 30A
- Extra features: Four stage battery charging, temperature compensation, LCD screen, PC software, supports remote meter and multiple load control methods.
- The high points: A cheap MPPT controller compared to other top-tier models with great safety protections.
- The low points: Doesn’t offer as high of a max input voltage or max current output as other MPPT models.
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When it comes to MPPT controllers, they reign king in terms of battery regulation. There are MPPT models out there that come with more bells and whistles.
However, the Epever solar charge controller tops the list for how cost-effective it is. It has a price point that’s close to half that of other high-quality models. But this charge controller puts in a lot of bang for your buck.
Overall, the Epever solar charge controller has an advertised high tracking efficiency rating of no less than 99.5%. The brand has other models with current outputs from 20A to 40A. However, the 30A version is a good middle ground for average buyers who aren’t looking to create huge solar arrays.
It’s also a great choice for those looking to create off-grid solar panel systems to power a home or bunker. With free system design and technical support from the company, Epever makes it super simple to harvest energy efficient and eco-friendly solar power.
What do reviewers say?
Buyers rave about the stellar price point of a high quality MPPT solar charge controller. They have used the device to regulate solar panels placed on travel trailers, houses, ponds, and more. They claim that it’s easy to install and use because of the remote display.
Some users have had failed controllers. But they report that the manufacturer’s customer service was fast and friendly. Reviewers also appreciate the plethora of functions. Those include load output for lighting and battery use control.
Features & Considerations
The Epever MPPT solar charge controller has an automatic system voltage recognition of 12 to 24V, and an auto-saving function to remember settings. The unit also comes equipped with a multi-function LCD display system to display information and can also be connected to PC software or an MT50 tracker for constant monitoring.
The charge controller works with gel, sealed and flooded lithium battery types, and has multiple load control modes, including manual, lighting, and light timer. Not only that, but the controller comes packed full of safety protections, including battery overvoltage, load overload, PV short circuit or reverse polarity and more.
Outback Flexmax 80 FM80 MPPT 80 AMP Solar Charge Controller
- Type: MPPT
- Battery voltage: 12-60V
- Max input voltage: 150V
- Max current output: 80A
- Extra features: Programmable, backlit display, logged system performance data, temperature control, and network integration capable.
- The high points: Can handle high amounts of DC volts and convert them to 12VDC to 60VDC for battery banks.
- The low points: Very high price point for system and customizable additions.
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The Outback Flexmax FM80 is one of the best solar controllers on the market as it supports a wide variety of system designs and battery types. With a huge max input voltage capacity, the Outback controller is perfect for off-grid systems that people installed on roofs or rural areas.
One of the key selling points for this device is its capacity for streamlined management and programming. The manufacturer also allows for more advanced configurations when connected to the MATE system display and controller, or a branded inverter and a HUB communications manager.
Beyond its ease of use, the manufacturer designed the Outback solar charge controller with a discreet black case and green screen. This unit is a great addition to any solar panel system design for advanced and beginner solar aficionados.
What do reviewers say?
Product users are overall very happy with the Outback brand. This model is no exception.
With sturdy construction and high-quality design, reviewers have few complaints. Those who do face issues claim that that the manufacturer’s customer service is prompt and effective. They report that they solve problems quickly.
One buyer was not happy that it did not come with a data cable. That is necessary to connect the Outback controller to the HUB communications manager.
Because the package doesn’t include a cable, buyers must purchase one separately. That is, if they want to centralize their data logging and system management.
Features & Considerations
The Outback Flexmax advertises an increase of PV array output by up to 30%, which is higher than most other models on the market. The input PV voltage can handle up to 150VDC open circuit for charging batteries from 12 to 60VDC. With such a large voltage capacity, the Outback controller is great for grid tie solar panel systems.
The specific FM80 model also comes with a built-in 80-character display that shows data logs from the past 128 days. This data logging can be easily centralized using other advanced Outback tools, like an inverter, MATE3 controller and HUB communications manager.
With automatic temperature control, the device can use intelligent thermal management systems to cool the system to an ambient temperature. You can also supplement this with an optional remote temperature sensor that you buy separately.
Victron SmartSolar MPPT 100/50 Solar Charge Controller
- Type: MPPT
- Battery voltage: 12-48V
- Max input voltage: 150V
- Max current output: 100A
- Extra features: Bluetooth connection, remote management portal, battery monitor compatible.
- The high points: The advanced technology and intelligent management system makes it perfect for RVs.
- The low points: Requires an additional purchase for full battery monitoring.
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With an intelligent and lightning quick system, the Victron SmartSolar MPPT charge controller is a great choice for those unfamiliar or new to solar system installation. The digital features included with this MPPT controller, such as the wireless Bluetooth management system, puts this device on the top of the list.
Victron energy is well-known for being a high-quality manufacturer of power conversion equipment, and this model is no exception. Based in the Netherlands, Victron has been producing battery inverters and chargers since 1975, primarily for the auto and boat market.
What do reviewers say?
Buyers rave about Victron’s reputation for battery components, especially when it comes to solar panels placed on vehicles like RVs and boats. Of course, the most notable function is the Bluetooth option that connects with users’ smartphones. This is apparently particularly helpful when on the road.
However, some purchasers have claimed that technical support is not always readily available. That is concerning considering their main selling point is advanced technology. One buyer also claims that this controller damaged his batteries after it flooding it with power and overcharging.
Features & Considerations
The Victron SmartController offers built-in Bluetooth connectivity to any Bluetooth enabled device, such as a smartphone. Through an internet connection, users can use the Victron Remote Management Portal the MPPT controller anywhere for free. This is great for setting up, updating and monitoring remote systems like those installed in an RV.
You can also upgrade the controller with the additional purchase of the Victron battery monitor BMV-700 series. This add-on will monitor the battery bank. It provides live status information, like voltage, current, solar watts and more.
TIPS FOR BUYING YOUR SOLAR POWER SYSTEM.
Buying a home solar power system can be a very exciting experience, but don’t get too carried away by advertising. Be sure to focus on the important aspects of your purchase as it’s a substantial investment and one you’ll be living with for a long time. The following are some buying solar tips on what to look for when purchasing a system.
Ask friends, family neighbours or colleagues who have had solar PV systems installed. Often the best buying solar tips com from right in your neighbourhood. They’ll be able to tell you about their experiences and perhaps alert you to any problems they experienced. Problems that you’ll be able to avoid. Learn more about potential issues in our consumers guide to solar power – avoiding tricks and traps.
Length of manufacturer’s warranty
Take note of what guarantees the manufacturer offers. If the manufacturer is reputable and the warranty period on the panels is substantial (at least 25 years) you would naturally expect your solar system to last long for a long time, long enough to pay for itself and make you a profit. However, for a warranty to be honoured, the manufacturer needs to be still operating. So, be cautious of brands without a track record in Australia.
Have realistic price expectations
If you are paying substantially less than many other similar size systems quoted, you may find poor quality equipment and/or poor installation work. Quality equipment and installation isn’t cheap and, like all other purchases, you often get what you pay for.
Compare components and warranty periods and check into the company providing the installation. While large, well established companies can pass on substantial savings due to increased buying power, other companies often reduce costs by cutting important corners.
Solar panel certifications
This applies to all solar panel purchases, but especially to the purchases that could attract a government rebate. The certification on solar panels indicates the type of testing that they have undergone. For instance, TUV IEC 61215 confirms that the solar panels have gone through testing by an independent laboratory and have met their advertised specifications. Other certification types are often self-assessed. Therefore, they rely on the company being honest in what it claims.
Decide on the type of panels
It used to be the case that if you had limited roof space you would need highly efficient (and very expensive) mono-crystalline solar panels. This is rapidly changing with advances in polycrystalline panel technology and some thin film technologies. Still, even if you have ample roof space you may still want to consider panel sizes vs. output. Filling up your roof with inefficient panels will affect your ability to add more panels at a later date, and does not maximise the power output of the space.
It’s also important to bear in mind that regardless of claim, no solar panel technology will produce a significant amount of power in full shade. Learn more about monocrystalline vs. thin film panels.
Solar panel mounting
Make sure that the roof, ground mounting or tracking system is engineer certified for the area you are in. For example, if you live in a cyclone prone area make sure the mounting system and mounting brackets are also cyclone rated. Quality systems are wind certified. After all you do not want your system to take off during a wild storm . The mounting system is a very vital component and some suppliers skimp on this item. Make sure you ask about wind certification, warranty arrangements and get copies of relevant documents.
Solar inverter efficiency
A power inverter is the box between the panels and your appliances that converts DC electricity from solar panels to AC suitable for use in your home.
Not all solar inverters are equal and inverter efficiency will have a direct impact on the amount of time it takes for a system to pay for itself. Look at the inverter efficiency before purchasing a system. Obviously, the more efficient the inverter the better. Less electricity will be wasted as heat during the conversion from DC to AC. Industry leading solar inverters for grid connect systems in Australia include SMA, Sungrow and Fronius. Be cautious of generic type brands.
Get a few solar quotes
It always wise to gather a few solar quotes when making a major purchase as you will find that prices vary widely between providers. But don’t be just swayed by price as inferior components can reduce the up-front cost of the system. However, they may wind up costing you more in the long run in terms of reliability and efficiency.
Avoid high pressure sales people
High pressure sales tactics are unfortunately common in the solar industry. Try not to make decisions on the spot, just ask the person to let you consider the offer. If it’s as good as they claim, it will still be a good deal tomorrow. Pressured decisions on the spot often turn out to be less advantageous in reflection.
High pressure sales people are only one of the pitfalls that may await you when you shop for a solar power system. Learn more about the potential issues and how to avoid them in our consumers guide to solar power – avoiding tricks and traps.