Best MPPT Charge Controllers
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I spent weeks testing 5 of the best MPPT solar charge controllers on the market.
I built a custom testing setup and tested their ease of use, build quality, and power output. I also researched their specs and spent time using their mobile apps to monitor my system and create custom charging profiles.
Based on all that, here are my reviews and recommendations.
Quick Recommendations: Best MPPT Solar Charge Controllers
Here’s the TLDR version of my rankings:
- Top Pick:Victron SmartSolar MPPT 100/30
- Budget Pick:Renogy Rover 40A
- Honorable Mention:EPEver Tracer 4215BN
- Renogy Rover Elite 40A
- EPEver Tracer 4210AN
Or keep reading for my full MPPT charge controller reviews.
Note: Most of the charge controllers I tested offer models with different charge current ratings, max PV voltages, and/or compatible battery voltages. So if you see one on this list you like, but it isn’t compatible with your system, just search for the other available models and you’ll probably find one that is.
Top Pick: Victron SmartSolar MPPT 100/30
|Rated charge current:
|Max. PV open circuit voltage (Voc):
|LiFePO4, sealed (AGM), gel, flooded, custom
|Max. PV input power:
|440W @ 12V, 880W @ 24V
|Max. wire size:
|6 AWG (16 mm2)
Pros: Easy to use, built-in Bluetooth, robust mobile app, custom charging profiles
Cons: Expensive, mediocre wire terminals, no screen
Best for: Those looking for the best MPPT charge controller who don’t mind paying top dollar; advanced users who want the most features and customizability
For the sake of everyone’s wallets, I almost hoped the Victron wouldn’t be my favorite. But it was.
Out of the box, I found the Victron to have the most features and be the easiest to use. It’s about as “plug and play” as it gets.
Bluetooth is built in to all the models in the Victron SmartSolar MPPT product line. Once the Victron is installed, you can use the free VictronConnect mobile app to monitor and customize your system.
The Victron was the only MPPT I tested with Bluetooth built in. All the other charge controllers in this review make you buy a 30-40 Bluetooth module for that feature. That helps justify the Victron’s price a bit.
The VictronConnect app has a lot of features. It can be a little overwhelming at first. But, once you learn your way around it, it can be quite powerful. You can use one of the many battery presets or, for advanced users, easily create and save custom charging profiles.
And that’s just the tip of the iceberg. Victron makes all sorts of accessories — sensors and shunts and the like — that can pair with the app as well and communicate with your controller to customize and optimize your system. It’s a solar nerd’s playground.
I also performed a power output test and the Victron placed first — by a hair. I wouldn’t put too much stock in these results because of the variables I couldn’t control (e.g. panel temperature, fluctuations in solar irradiance), but it was nice to see a first place finish from a top-of-the-line MPPT.
The Victron’s wire terminals are passable, but nothing to write home about. The screws felt high quality, but the terminals themselves were shallow and a little too close together for my taste.
Otherwise, the build quality of the Victron felt solid. The case and heat sink seem durable. It was also the smallest and lightest controller I tested, if that’s an important factor in your system.
I tested the bestselling Victron SmartSolar MPPT model on Amazon at the time of my research, which happened to be the 100/30 model (100V PV voltage limit, 30A charge current rating).
But Victron has a huge product lineup and sells SmartSolar controllers with a wide range of PV voltages (75-250V) and current ratings (10-100A). So if the model I’ve tested is too much or too little for your purposes, you can upgrade or downgrade accordingly.
Budget Pick: Renogy Rover 40A
|Rated charge current:
|Max. PV open circuit voltage (Voc):
|LiFePO4, sealed (AGM), gel, flooded, custom
|Max. PV input power:
|520W @ 12V, 1040W @ 24V
|Max. wire size:
|8 AWG (10 mm2)
|Yes (requires additional purchase)
Pros: Great value, easy to use, good mobile app (must buy Renogy BT-1 Bluetooth Module to use), custom charging profiles
Cons: Not compatible with Renogy Battery Voltage Sensor
Best for: Those looking for the best bang for their buck
I’ve had the Renogy Rover 40A for over 6 months, and I’ve become quite familiar with it during that time.
It’s well-priced and easy to use. It’s compatible with all the most common types of solar batteries, plus has the option to create custom charging profiles.
Renogy has a mobile app called Renogy DC Home. To use it with the Rover 40A, you’ll have to buy the Renogy BT-1 Bluetooth Module.
The Renogy app is good, but I found it a little less feature-rich than Victron’s. For many users it will have everything you need. I suspect advanced users may want a little more customization, though.
The Rover’s wire terminals were good but not great. The terminals felt roomier than the listed max wire size, but the screws were a little loose and hard to tighten at times.
The screen on the Rover 40A displays nearly every system spec I could hope for. It’s also easy to use it to select your battery type, edit load settings, and create custom charging profiles.
In my power output test, the Rover tied for last with the EPEver Tracer 4210AN. They both output a max of 142 watts compared to the 146 watts of the Victron which placed first. I think the difference of 4 watts is negligible.
The Rover 40A doesn’t have a port for connecting a battery voltage sensor, which I don’t love. You have to upgrade to the Rover 60A or Rover 100A for that feature. Battery voltage sensors help charge controllers adjust their charging voltage to account for voltage drop, which is helpful in certain systems.
Overall, the Rover 40A is a good MPPT charge controller for the money. It has all the features and battery presets you need to set up your system quickly and easily. And for more advanced users, you can create custom charging profiles and buy the BT-1 Bluetooth Module for remote monitoring.
Honorable Mention: EPEver Tracer 4215BN
|Rated charge current:
|Max. PV open circuit voltage (Voc):
|Sealed (AGM), gel, flooded, custom
|Max. PV input power:
|520W @ 12V, 1040W @ 24V
|Max. wire size:
|4 AWG (25 mm2)
|Yes (requires additional purchase)
Pros: Excellent build quality, my favorite wire terminals, 150V PV voltage limit
Cons: Must make custom charging profile if using with lithium batteries, Bluetooth monitoring is harder to set up
Best for: Those looking for a charge controller with great build quality; users with lead acid batteries; users with lithium batteries who don’t mind creating custom charging profiles
From a hardware perspective, the Tracer 4215BN — sometimes called the Tracer BN or Tracer BN Series — was my favorite charge controller.
It’s big and heavy and virtually one entire heat sink. The wire terminals were easily my favorite. They felt like tanks. And they’re the biggest in this review – capable of handling up to 4 AWG wire. If you like to overgauge your wires, this is one to consider.
However, the hardware in a charge controller isn’t the full story. Charge controllers also have a software component. When that’s lacking, it makes the controller harder to use.
I didn’t test the EPEver app, but from reviews I’ve read it’s a little clunky. The included MT50 screen is great, though. It’s easy to view all your system specs and select your battery type. If you’re using lead acid batteries, the Tracer BN is about as plug and play as any other MPPT.
But it has no preset for LiFePO4 batteries. You’ll have to create your own custom charging profile if using lithium. It isn’t that hard to do, but it’s certainly not as easy as selecting your battery type from a menu.
These usability hurdles are small, but more noticeable than on the other controllers in this review. If you’re comfortable with technical product manuals, they shouldn’t be difficult to overcome. And, once you do, you’ll have a great controller that feels like it could last a lifetime.
As a final heads up, the Tracer BN’s days might be numbered. While doing research for this article, I tried to find this controller on EPEver’s website, but couldn’t.
From years of product testing, I’ve come to see these removals as the first sign of a product’s discontinuation. For now it’s still available on Amazon, but time will tell.
Renogy Rover Elite 40A
|Rated charge current:
|Max. PV open circuit voltage (Voc):
|LiFePO4, sealed (AGM), gel, flooded
|Max. PV input power:
|520W @ 12V, 1040W @ 24V
|Max. wire size:
|6 AWG (16 mm2)
|Yes (requires additional purchase)
Pros: Cheapest MPPT tested, good mobile app (must buy Renogy BT-2 Bluetooth Module to use)
Cons: No custom charging profiles
Best for: Those who want a cheap MPPT and only plan to use preset battery charging profiles
Based on its name, I wouldn’t fault you for assuming the Renogy Rover Elite is a more advanced version of the Renogy Rover. I know I certainly did.
But you’d be wrong. It’s actually a cheaper version. (Whose idea was that?)
The Rover Elite was close to being one of my recommended picks. It has a lot going for it: It’s the cheapest MPPT I tested. It’s compatible with all the main types of solar batteries. And, if you buy the Renogy BT-2 Bluetooth Module, you can connect the Rover Elite to the Renogy app to monitor your system from your phone.
Based on that, I think it’s a good budget option for DIY solar beginners, or users who just plan on using the battery presets.
But if you want to create custom charging profiles, know that the Rover Elite doesn’t have that option. I know from plenty of reader emails and Комментарии и мнения владельцев that advanced users like to customize their charging setpoints.
Unlike it’s more expensive cousin, the Rover Elite does have a battery voltage sensor port. You can buy a Renogy Battery Voltage Sensor and connect it to the Rover Elite to improve the controller’s battery voltage reading.
I’ve tested a handful of Renogy products over the years, and I always seem to come to the same conclusion: they’re good quality for the price. The Rover Elite is the same. Overall, it’s a good cheap MPPT.
EPEver Tracer 4210AN
|Rated charge current:
|Max. PV open circuit voltage (Voc):
|LiFePO4, sealed (AGM), gel, flooded, LiNiCoMnO2, custom
|Max. PV input power:
|520W @ 12V, 1040W @ 24V
|Max. wire size:
|6 AWG (16 mm2)
|Yes (requires additional purchase)
Pros: Fast power point tracking, custom charging profiles
Cons: Not the easiest to use, mediocre wire terminals
The Tracer 4210AN — sometimes called the Tracer AN or Tracer AN Series — is a solid controller.
But, when pitted side by side against the others, it didn’t stand out to me in any way. I’m not sure what type of user I’d recommend it for.
I think it’s a good value for the money, but not as good as the Renogy Rover. The build quality is solid but not outstanding. I think the wire terminals are subpar.
On startup, it did track the maximum power point the fastest of any controller tested (in about 9 seconds on average, compared to the 57 seconds of its sibling, the Tracer 4215BN, which placed last). That’s something, I suppose.
It has a good screen and, on Amazon at least, the 40 amp model comes with the MT50 display included.
But I do want to underscore that this is a well-made unit. It works well, is solidly built, and even has the lowest power consumption of those tested. EPEver claims ≤12mA (it doesn’t say at what voltage), which is less than the 30mA (at 12V) of the Victron, the next closest.
If this controller is on sale, or you just prefer the EPEver brand, I’d say go for it. If it was the only MPPT I owned, I expect I’d end up being perfectly happy with it.
How to Choose the Best MPPT Charge Controller for Your Needs
Rated Charge Current
Also called: rated battery current, battery charge current or rated output current
The rated charge current is the maximum amount of current (in amps) that the charge controller can charge the battery at. It’s such an important number that it’s often included in the product name (e.g. Renogy Rover 40A — “40A” is the rated charge current).
30A-40A: Many popular MPPTs (including all the ones I tested) fall in this range. They can usually handle between 400-500 watts of solar at 12 volts and 800-1000 watts of solar at 24 volts. They’re best used with lithium batteries of 80Ah or greater and lead acid batteries of 130Ah or greater.
40A: MPPTs with charge current ratings greater than 40 amps are designed for large solar systems. They can usually handle greater than or equal to 600 watts of solar at 12 volts and 1200 watts at 24 volts. Some may also be compatible with 36V and 48V batteries and capable of handling even greater PV power inputs at these voltages.
Note: Charge controllers with load terminals may also list a rated discharge current (aka rated load current). This is how much current the controller can output through its load terminals.
Maximum PV Voltage
Also called: maximum PV open circuit voltage, maximum input voltage
Use our solar panel voltage calculator to calculate the maximum open circuit voltage of your solar array. Then, pick a charge controller with a maximum PV voltage greater than this number.
100V-150V: This is the most popular PV voltage range for MPPT charge controllers. Models in this range can usually handle 3-6 12V solar panels wired in series.
150V: MPPTs in this range are designed for large solar arrays. They can usually handle 7 or more 12V solar panels wired in series.
Note: Estimating the max voltage of your solar array is not as simple as multiplying open circuit voltage by the number of solar panels wired in series. This is because solar panel voltage increases as temperature drops. To get an accurate estimate, you’ll have to correct for temperature.
Also called: system voltage, nominal battery voltage
This number refers to the nominal battery voltage the controller is compatible with. You may see the word “auto” next to the battery voltage — e.g. “12/24V Auto.” This means the charge controller automatically detects whether you’re using a 12V or 24V battery bank.
12/24V: Many popular MPPT models are compatible with 12 and 24 volt batteries. Indeed, these are the compatible battery voltages of all the models I tested for this review.
12/24/48V: There are higher-end MPPTs compatible with 12, 24 and 48 volt batteries. These are usually MPPTs with higher charge current ratings.
12/24/36/48V: Some brands sell models that are also compatible with 36 volt batteries.
Note: Some charge controllers also list a max battery voltage in their spec sheet. As you’d expect, you don’t want your battery voltage to exceed this number.
Compatible Battery Types
Make sure the charge controller you’re getting is compatible with your type of battery.
Here are the most common types of solar batteries:
- LiFePO4 (Also referred to as lithium iron phosphate, LFP, or simply “lithium”)
- AGM/Sealed lead acid
- Flooded lead acid
If a controller is compatible with a type of battery, it essentially means it has a preset charging profile for that battery chemistry that you can select when you set up the controller.
Custom charging profiles: Many MPPT controllers also offer the ability for you to create custom or “user” charging profiles. These let you select all the voltage setpoints — such as absorption voltage and float voltage — so you can tailor it for your specific battery.
In essence, custom profiles make the controller compatible with all main types of solar batteries. Many advanced users also like to adjust these numbers to try to maximize their battery lifespan.
Maximum PV Input Power
“PV” refers to solar panels, so this number is the max solar array wattage you can connect to the controller.
You’ll notice that the controller has different max PV input power ratings for different voltages. This is because watts is based on both volts and amps (W = V A).
If you’re having trouble figuring out what charge current rating you need, you can also refer to this number for guidance.
Being able to monitor and control your solar system from an app on your phone is great convenience. Don’t underestimate how nice it can be! MPPT controllers fall into three different buckets here:
Built-in: Some controllers have Bluetooth built in, meaning you don’t need to buy anything in order to start monitoring your system from your phone. Of the controllers I tested, only the Victron SmartSolar came with Bluetooth built in.
Additional purchase required: A lot of controllers require an additional purchase before you can use Bluetooth monitoring. You have to buy a Bluetooth module that connects to the controller. These typically cost 30-40. The remaining 4 controllers I tested fall into this bucket.
No Bluetooth: Some MPPT charge controllers come with no Bluetooth capabilities at all. The only way to monitor your system with these is through the screen or LED lights on the controller.
Look for good wire terminals with quality screws. Cheap charge controllers skimp on their wire terminals and you’ll notice right away. They’re easier to strip and you can’t tighten the screws down as much. They may be quicker to loosen over time.
Some people also like to over-gauge their wires. Thicker wires help minimize voltage drop and make it easy to expand your system later on. If that’s you, you’ll want to pay attention to max wire size.
Charge controllers consume a modest amount of power, which will be listed on the specs sheet. In most DIY solar systems, the power consumption isn’t enough to make a material difference.
However, power consumption can come into consideration if your solar panels will go for long stretches without receiving sunlight. For instance, one reader from Scandinavia wrote to me about how charge controller power consumption factored into his buying decision because the solar panels on his off-grid cabin were covered in snow for most of the winter. He didn’t want the charge controller to consume so much power that it fully drained his batteries.
In these situations, look for a controller with low power consumption. Most charge controllers have lower power consumption at lower system voltages, so you may want to keep your battery bank at 12 volts. PWM charge controllers tend to consume less power than MPPTs, so you may want to also consider a PWM model.
If you’re using lead acid batteries and they’ll be experiencing wide temperature swings, you should look for a charge controller that adjusts its voltage setpoints based on temperature — a featured called temperature compensation. Lithium batteries don’t need temperature compensation.
To have this feature, the controller needs to have a temperature sensor. The sensor will either be a built-in internal sensor, or an external sensor included in the box or available as an additional purchase.
If it’s an external sensor, You plug it into the temperature sensor port on the controller and then tape the probe to the battery.
Operating Temperature Range
Pay attention to operating temperature range if your charge controller will be experiencing wide temperature swings — such as if it’s located in a boat, RV, or campervan without AC. The higher-end models are typically able to handle wider temperature ranges.
MPPT vs PWM Charge Controllers
MPPT charge controllers are more expensive, but more efficient. Most are around 95% efficient.
PWM charge controllers are cheaper, but less efficient. They are around 75-80% efficient.
What’s more, MPPT controllers often have higher charge current ratings, such as 30 amps or more. This means you can connect more solar panels to them. (The MPPT models included in this test, for instance, can handle solar arrays of 400-1000 watts depending on system voltage.) They also have higher PV voltage limits, so you can connect more panels in series which can save you money on wiring.
PWM charge controllers usually have lower charge current ratings, such as 10-30 amps, making them best suited for solar arrays of 400 watts or less. They often only have high enough PV voltage limits for 1-2 12V solar panels in series. If you’re using lots of solar panels with a PWM, you’ll probably have to wire them in parallel which can increase wiring costs.
The Bottom Line
I liked all of the MPPT charge controllers I tested for this review. I’d be happy to have any of them in my system. Alas, the job of a reviewer is to rank the options from best for worst.
After testing 5 MPPTs side by side and comparing their spec sheets, I think the Victron SmartSolar MPPT is the best MPPT charge controller on the market. I thought it had the best build quality and was the easiest to set up and use.
The Renogy Rover 40A has the best bang for your buck. It’s a well-made model that can be paired with Renogy’s mobile app if you also buy the BT-1 Bluetooth Module.
Lastly, the EPEver Tracer 4215BN is built like a tank and has the best wire terminals of any charge controller I’ve ever used. It’s not compatible with lithium batteries out of the box, but you can use the included MT50 screen to create a custom charging profile.
As a reminder, all the charge controllers I tested offer models with different charge current and PV voltage limits. If you like the Victron, for instance, but need a higher current rating, consider the Victron SmartSolar MPPT 100/50. It has a 50 amp current rating, compared to the 30 amp rating of the model I tested.
A small ask: If you found my MPPT charge controller reviews helpful and are planning to buy one, please consider buying through one of my affiliate links below. I’ll get a small commission (at no extra cost to you) which will help fund more reviews like this one. Thank you!
Midnite Solar Classic 200, MPPT Charge Controller, 63-79A, 12-72V FEATURES The Classic 200 MPPT Charge Controller has Arc Fault, Ground Fault, free web monitoring, a graphics panel and Solar, Hydro and Wind Modes. The Classic 200 has a maximum.
Midnite Solar Classic 150, MPPT Charge Controller, 76-96A, 12-72V FEATURES The Classic 150 MPPT Charge Controller has Arc Fault, Ground Fault, free web monitoring, a graphics panel and Solar, Hydro and Wind Modes. The Classic 200 has a maximum.
Rich Solar 40 Amp MPPT Solar Charge Controller FEATURES Automatically detects 12V or 24V DC system voltages. Compatible with various deep cycle battery options: Sealed, Gel, Flooded, and Lithium. Innovative MPPT technology with high.
Rich Solar 60 Amp MPPT Solar Charge Controller FEATURES Automatically detects 12V/24V/36V/48V DC system voltages. Compatible with various deep cycle battery options: Sealed, Gel, Flooded, and Lithium. Innovative MPPT technology with high.
36V/48V Rover Boost 10A MPPT Solar Charge Controller The 10A Rover Boost charge controller is a unique solution that allows you to charge 36V or 48V battery banks with 12V or 24V low voltage solar panels—specially designed for golf carts and.
Renogy Rover Elite 40A MPPT Solar Charge Controller The Rover Elite series of MPPT charge controllers give you the most efficient charging for countless 12V or 24V off-grid solar applications. Compatible with an assortment of batteries, including.
Renogy LCD Remote for Inverter Charger The Renogy LCD Remote is designed to be used exclusively with a 1000W, 2000W or 3000W Pure Sine Wave Inverter Charger. The LCD Remote allows for remote monitoring of the Inverter Charger’s performance. With.
Renogy Battery Temperature Sensor for Voyager Charge Controllers Perfect for solar systems that experience varying temperature changes throughout the year, The new edition Voyager RTS optimizes battery performance and extends its lifespan.
Renogy Rover Elite 20A MPPT Solar Charge Controller he Rover Elite series of MPPT charge controllers give you the most efficient charging for countless 12V or 24V off-grid solar applications. Compatible with an assortment of batteries, including.
Renogy New Edition Voyager 20A PWM Waterproof Solar Charge Controller Featuring a blue back-lit LCD displaying system information including error codes, the Voyager 10 amp charge controller is engineered to be of world-class quality. Not only is.
Renogy New Edition Voyager 10A PWM Waterproof Solar Charge Controller Featuring a blue back-lit LCD displaying system information including error codes, the Voyager 10 amp charge controller is engineered to be of world-class quality. Not only is.
Renogy Rover 100 Amp MPPT Solar Charge Controller Bluetooth Module Introducing the new 100A Rover MPPT Charge Controller, the largest Rover controller that Renogy has to offer. Capable of supporting up to 1300 watts on 12 volts, 2600 watts on 24.
Solar charge controllers are devices that regulate the flow of electric current from solar panels to batteries. They prevent overcharging, over-discharging, and can extend the life of the battery.
There are two main types of solar charge controllers: Pulse Width Modulation (PWM) and Maximum Power Point Tracking (MPPT).
PWM controllers regulate the charge flow by rapidly turning the power on and off to maintain a constant voltage. As the battery gets closer to being fully charged, the controller reduces the amount of power it sends to the battery to prevent overcharging. PWM controllers are generally less expensive than MPPT controllers but are less efficient, especially in low-light conditions.
MPPT controllers use advanced electronics to track the maximum power point of the solar panel and adjust the voltage and current to optimize the amount of energy transferred to the battery. They can be up to 30% more efficient than PWM controllers, making them a better choice in low-light conditions or for larger systems.
In summary, while both PWM and MPPT controllers can effectively manage the charging of batteries from solar panels, MPPT controllers are generally more efficient and suitable for larger systems, while PWM controllers are more affordable and suitable for smaller systems.
Q: What is a solar charge controller?
A: A solar charge controller is an electronic device that regulates the amount of charge going to and from a battery bank in a solar power system. It is used to prevent overcharging and prolong the life of the batteries.
Q: What is the difference between a PWM and MPPT solar charge controller?
A: A PWM (Pulse Width Modulation) controller is a basic type of controller that works by reducing the voltage of the solar panel to match the voltage of the battery bank. An MPPT (Maximum Power Point Tracking) controller is more advanced and uses a tracking algorithm to adjust the voltage and current of the solar panel to optimize power output.
Q: What are the benefits of using an MPPT solar charge controller?
A: MPPT solar charge controllers are more efficient than PWM controllers, as they can extract more power from the solar panels. They can also handle higher input voltages and allow for longer cable runs between the panels and the controller.
Q: What are the benefits of using a PWM solar charge controller?
A: PWM solar charge controllers are simpler and less expensive than MPPT controllers.
Q: What factors should be considered when choosing a solar charge controller?
A: When choosing a solar charge controller, consider factors such as the system voltage, current rating, and the type of battery being used. It is also important to ensure that the controller is compatible with the solar panels and other components of the system.
Q: Can a solar charge controller be used with any type of solar panel?
A: Solar charge controllers can be used with most types of solar panels, but it is important to ensure that the controller is compatible with the voltage and current output of the panels.
Q: Can a solar charge controller be used with any type of battery?
A: Solar charge controllers are designed to work with specific types of batteries, such as lead-acid or lithium-ion. It is important to choose a controller that is compatible with the type of battery being used. Most modern controllers can work with multiple battery types.
Q: How is a solar charge controller installed?
A: Solar charge controllers are typically installed between the solar panels and the battery bank. The installation process involves connecting the controller to the solar panels and the battery bank using appropriate wiring and connectors.
Q: How much does a solar charge controller cost?
A: The cost of a solar charge controller varies depending on the type, capacity, and manufacturer. PWM controllers are generally less expensive than MPPT controllers.
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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.
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.
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.
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.
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.
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.
Solar Charge Controllers
Solar charge controller, also known as a battery charge controller, charge regulator, or battery regulator is a device that provides safe charging and operation of the solar battery.
The solar charge controller is an important component of the solar power system. It protects solar deep cycle batteries against overcharging and overvoltage and extends battery’s service life by preventing its complete draining. Whenever you are using an energy storage in your solar panel system, lead-acid or lithium battery, you should add a solar charge controller.
What does a solar charge controller do?
The primary function of a charge controller is to keep your battery safe from high voltage of your solar array. There are two types of charge controllers for solar panels: PWM (pulse width modulation) and MPPT (maximum power point tracking) controllers, and they handle this primary task differently.
PWM-controllers simply bring the voltage of a solar panel down to the level of a battery. This type of solar panel controller is cheap and usually has a longer lifespan than MPPT-controllers – more than 15 years on average. However, it’s quite inefficient and doesn’t fit every solar panel system.
MPPT-controllers, on the other hand, convert high voltage panels into electric charge for a battery, maximizing the efficiency of a system. They are more expensive and last for 10-15 years. In short, MPPT solar panel charge controllers allow you to use your array at full electric power.
Besides handling panels’ high voltage, solar panel controllers
- prevent overcharging of a battery, much like a “Smart” battery charger;
- don’t allow the usage of a battery in the state of a deep discharge;
- block reverse currents, which flow from battery back to panels at night and can potentially start a fire.
Choosing the right solar charge controller
Every battery charge controller has two main parameters that you should look out for: maximum amps size and maximum voltage. To calculate the minimum amps of a solar panel controller, divide the combined power of your array by a voltage of your battery and add 20% on top just to be safe. To calculate the voltage of your solar panel system, combine VOCs (open circuit voltage) of all panels. When it’s cold and sunny, panels can reach their peak voltage (Vpp), so add 5V on top of VOCs for every panel for safety. This way you’ll get the required minimum voltage of your solar panel charge controller.
Don’t forget that the current and voltage of your system depend on the type of connection that you choose. Connection in series gives you combined voltage of all panels, while an amperage stays the same. The connection in parallel allows you to keep the voltage low, but raises the current. Parallel-series type of connection gives you an option to adjust the voltage and current to the properties of your charge controller — just don’t mess up the electric wiring.
Solar charge controllers come in a variety of types and many offer additional features and options:
- Networking and communications capabilities.
- Metering and data logging.
- Battery system monitoring.
- Availability of automatic settings.
- Programming options.
Popular brands of solar charge controllers
While the solar panel market is dominated by Chinese manufacturers, American and European companies make the best battery charge controllers. Here are a few well-known names that you can find in our store.
Some experts consider Midnite Classic, a famous model by an American brand, to be the safest controller on the market because of Arc Fault Detection technology. The Midnite Classic charge controller can be paired with batteries of a different voltage – from 12V to 72V. The MPPT technology maximizes the production of your system.
You can manage the controller’s settings remotely. You can connect the device to the Internet via Ethernet. Midnite Classic records logging data and has 20 Megabytes as storage. The regulator comes with a 5-year warranty. You can find this solar charge controller for sale in our store.
Morningstar still offers PWM solar charge controllers as well as more modern MPPT (maximum power point tracking) regulators. The key difference between the two is the way they handle higher voltage of panels.
- PWM controllers simply cut the voltage of panels down to the level of the battery. They are simpler and as a result cheaper and last longer. Their lifetime exceeds 15 years.
- MPPT regulators use extra voltage of panels and convert it into current for battery, using the electric power of your solar array to the maximum. They are very efficient, but the MPPT solar charge controller price is higher. Their lifetime is about 10-15 years.
Every Morningstar charge controller has a warranty for at least 5 years. The company’s product is known for high reliability and top efficiency.
OutBack Power is an American company founded in 2001. Their controllers are best suited for residential solar installations. The built-in fan ensures the cooling of a device. The average power consumption of an Outback solar charge controller in standby mode is usually less than 1W. The overall efficiency of the Outback solar power controller system reaches as high as 98.44%.
The American engineers worked hard to make their controller adjustable to the needs of a customer. You can program the controller to your liking and manage the charging process as you prefer. Of course, you can perform the equalization of a battery with OutBack controllers, much like with a Smart charger. Every controller is equipped with a display that allows you to monitor the state of your battery and panels.
Schneider Charge Controller
The European company Schneider Electric has been on the solar market for more than 20 years now. Schneider charge controllers are a good choice for homeowners that want to build an off-grid or a hybrid solar installation.
Schneider charge controller controls the charging process and offers all sorts of protection for your battery, including over-temperature protection. It blocks reverse currents and prevents overcharging and state of deep discharge.
Just like a solar inverter, a Shneider charge controller monitors your system. A regulator measures the battery charge and its temperature, notifying you when it goes too high. The warranty for a Shneider solar charge controller is issued for 5 years and you can expect it to last 10-15 years.
Why buy from us
We have a wide selection of solar charge controllers in stock. Call us, and our A1 SolarStore experts will answer all of your questions about solar charge controller cost, shipping and warranty.
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What Is a Solar Charge Controller and Do You Need One?
A solar charge controller is a key component of a solar panel and battery system. It controls the rate and level at which the batteries are charged by incoming DC (direct current) power. Without a charge controller, incoming power could cause damage to your battery bank, and power from your battery could leak back into your solar panels, which is unsafe and could cause damage.
Understanding how solar panel charge controllers work and the different types of solar charge controllers will help set you up for success while planning for an off-grid solar installation.
What Does a Solar Charge Controller Do?
A charge controller is used to connect solar panels to batteries and ensure power travels safely and efficiently between them. They have a few main functions:
- Control the amount of power sent to the battery
- Prevent the battery from overcharging
- Ensure power only flows from the panels to the battery, never in the opposite direction
All of these are important and play a role in your solar system’s performance, but the most important function of a solar controller is to prevent overcharging. Solar charge controllers work by continuously monitoring the voltage of the battery and calculating the amount of additional energy that’s needed to fully charge it. They make sure enough power is sent to the battery to provide a full charge, but not so much that the battery’s voltage is increased to an unsafe level. If additional power is sent to the battery that exceeds its maximum voltage limit, serious damage can occur.
Types of Solar Charge Controllers
Just like there are different types of solar batteries. there are also different types of solar charge controllers. The two main types of charge controllers for solar panel systems are PWM solar charge controllers and MPPT solar charge controllers.
PWM Solar Charge Controllers
PMW (pulse width modulation) charge controllers are simpler and less expensive than MPPT controllers. They slowly reduce the amount of power flowing into your batteries and maintain a trickle of power when the batteries are full. To use a PWM controller, your solar panels and batteries must have matching voltages, which is most common in small systems.
MPPT Solar Charge Controllers
MPPT charge controllers (maximum power point tracking) are more sophisticated and expensive than PWM controllers. They regulate power flow more efficiently and ensure you’re saving as much power as possible from your PV panels. They can also pair panels and batteries that have different voltages, which is typical in larger and more complex solar systems.
Do You Need a Solar Charge Controller?
If your solar panel and battery system is tied to the grid, it’s unlikely that you will need a charge controller. In a grid-tied residential solar system, excess electricity is exported to the grid. So, when your battery is fully charged but your panels are still producing extra power, that power has somewhere to go and will not overcharge the battery.
Charge controllers are most commonly used in off-grid solar systems. If you’re planning to go off-grid with solar, you will likely need a charge controller to protect your battery bank. To learn more about off-grid solar installation, check out our beginner’s guide to off-grid solar.
Let Us Build a Custom Solar Energy System for Your Home
SouthFace Solar Electric specializes in off-grid solar installation in Arizona. We can help you choose the best solar products for your specific project, including the best charge controller. Our goal is to bring more power to you with a custom solar energy system that’s designed around your specific needs so you can go solar with no regrets. Our team has over 35 years of combined experience installing solar panels in Phoenix, Carefree, Scottsdale, Prescott, Chino Valley, and throughout the surrounding areas.