Our top pick for the best solar charge controller is Morningstar SS-10L-12V Sunsaver, which fits this description aptly. The fact remains that relying on sunlight as an energy source is sometimes a risky business. After all, who can predict the weather?
Technology has advanced in recent years, leading to better equipment and more affordable prices for solar charge controllers. That also means choices—and lots of them. That can make finding the best one for you difficult unless you have a grasp on what’s available and what options make sense for how you use solar, whether it’s for recreation or as a backup power source for your home.
Our guide will cover everything you need to know to pick the best solar controller for your boat, camp setup, or RV and its power grid, charge ability, and capacity. We’ll discuss the specs and features to look for in solar charge controllers along with some tips for getting the most out of your solar kit for reliable power when you need it.
Let’s get rolling!
The Morningstar SS-10L-12V Sunsaver is a reliable device if you need extra power than the standard one-panel system with 20 amps input voltage. It supports 12- or 24-volt batteries with a flooded or sealed select switch. You can use this PWM device on your boat too with its marine-rated terminals and fully encapsulated body. The size is compact for an easy installation that won’t take up a lot of room.
The LCD screen provides information on the charge status, battery level, and charging stage. It has safety protections for short circuit, lightning surges, and reverse current at night. It is a third-generation product that continues to get better and better. On the downside, it is more expensive than comparable models because of the electronics and casing.
Quality is definitely on the menu for this manufacturer with pre-testing, assembly in an ISO 9001 factory, and a Class 1, Division 2, Groups A-D, approved use for hazardous locations. Suffice to say that it is the only one of the controllers we reviewed with these credentials, making it the best solar charge controller for RV.
The range and features of solar charge controllers surprised us. To say that technology has advanced is a gross understatement. Today’s products are more efficient and user-friendly with added bells and whistles that optimize their usefulness. You’ll also find a wide spectrum of price points.
We selected devices for a variety of applications to help you pick the right one for your system and battery or battery bank.
The Renogy Wanderer 10 Amp Solar Charge Controller takes solar power to the next level with a controller that fits well with today’s lifestyle. It enters the Internet of Things realm with smart technology. You can manage load control remotely with the company’s smartphone app. It has optional Bluetooth connectivity to make it possible no matter where the road takes you.
The controller has several safety features baked into it, including protections for short circuit, overheating, and reverse current. It even has a self-diagnostic addition for troubleshooting power issues. It is a PWM unit with an LCD display with LED indicators that is easy to read and intuitive. We liked the fact that it has two USB ports so that you can charge your smartphone on the go.
The Renogy Wanderer was the only one of the controllers that were a truly smart device. The app provides a wealth of information for the solar power geek who wants to know everything about their system, including battery voltage. It also has an interface to connect with other users or tech support. Unfortunately, the developer hasn’t updated it since last year.
The max current output is 30 amps with an input voltage of 25 volts.
The EEEKit Solar Charge Controller is an excellent choice for smaller applications. The PWM controller can handle 12- or 24-volt batteries with a 30 amp capacity. The LCD display is bright and easy to read. The buttons are well-marked for quick, on-the-fly adjustments. It also has two USB ports to make it more user-friendly and versatile with the ability to charge other devices.
The installation is also simple with clear, albeit, brief instructions. It is a barebones charge controller without all the typical safety protections you’d see in more expensive models like the best MPPT solar charge controller. However, it works as described with lead-acid batteries and does provide reverse current and open-circuit protection. The unit isn’t overly attractive, but it is functional.
The casing is ABS plastic, which gives it some impact and heat resistance. While it didn’t seem flimsy, it did detract from the appearance. It’s inexpensive to replace, which is certainly a point in its favor. That also makes it a good choice for smaller applications.
The GHB Solar Charge Controller is a compact PWM device that measures only 5.1 inches long by 3.9 inches wide by 1.2 inches wide. It is well-constructed with a pleasing design. The buttons are well-marked with a bright LCD display that is easy on the eyes and less glaring than some products we’ve seen. It has a capacity of 20 amps and can work with 12- or 24-volt batteries.
The unit has several safety protections, including reverse polarity, lightning, and overcharging. It is compatible with any type of lead-acid battery. It has two USB ports, which we always like to see in these controllers. The controller is well-made to save energy, making it even more eco-friendly. Overall, the controller is a good value for the price.
It does what the product description states it will do. The design isn’t obtrusive. The operation is intuitive among the controllers that we researched. The fact that it has an on-off switch is another plus. The standout feature is the placement of the connectors. That puts it in the love-it-or-hate-it category for some among controllers.
The WindyNation Solar Charge Controller is the only controller we reviewed that is truly waterproof with an IP rating of 68. The PWM device has a lot more going for it. It has four-stage charging and includes the cables you’ll need to get up and running with your solar kit. The LED indicators on the LCD display give you a quick glimpse of your load status, solar charge, current, and battery level.
You can use the unit with either a 12- or a 24-volt battery with a 10-amp capacity. One unique feature is its Dusk/Dawn Voltage Sense, which acts as a timer to optimize battery life. Setting up the controller couldn’t be easier. While it doesn’t have a display, the instructions are well-marked under the lights. The controller is small at only 3 inches long by 2 inches wide by 0.8 inches thick.
The WindyNation Solar Charge Controller was the only product that stated it was waterproof among the controllers we reviewed. That makes it an excellent choice for outdoor applications such as a security light, especially since it doesn’t have a visible screen to monitor voltage and other specs.
The EPEVER MPPT Solar Charge Controller has a lot to offer the user looking for a high-efficiency unit with excellent safety protections. If you have concerns about your energy use, this model is worth a look. Like the other products we reviewed, it works with either a 12- and 24-volt battery. It has temperature compensation and four-staging charging to manage the current and voltage.
This MPPT charge controller was the only one that included a PC connection to keep the firmware updated. It’s an unexpected but welcome feature to take advantage of the latest technology and insights from its data logging. It also has a negative ground, overload protection, and overheating safeguard. It can even work with lithium-ion batteries for the ultimate in solar efficiency.
The EPEVER MPPT Solar Charge Controller was the only MPPT controller on our list, which was evident with the price. However, it’s still a wise purchase if you camp in challenging conditions and must have the reliability of the constant power of an MPPT unit. Depending on your investment in the other component of your solar kit, you may find it a smart buy and the best MPPT charge controller for the money.
The HQST PWM Solar Charge Controller is one of five products sold by this manufacturer and the only PWM model. This negative ground controller comes in at 30 amps. It has the usual roundup of safety protections like overheating, reverse polarity, and temperature compensation. You can use it with either lead-acid or a lithium-ion battery. It also has both a USB and an RJ12 data port.
The IP rating is only 30. That means it’s not water-resistant and can only handle modest protection against solid materials. While the screen is small, it has other lights that give you a decent summary of your system’s status and charge level. While it’s easy to install, the solar controller is not as simple to operate. That’s unfortunate since the instructions are lacking.
Overall, it is well-constructed and an excellent value for the price for a charge controller solar. While the front is plastic, the back is aluminum, which adds to its durability. The interface is user-friendly and intuitive, even if it doesn’t have all the extras you’d get in a higher-priced unit. It works as described with only occasional quality control issues.
To put getting the best solar charge controller in perspective let’s begin with how it works and the value it brings to your solar kit. The typical setup includes three or four components to manage the current and voltage, depending on the devices you need to power. They include:
The photovoltaic (PV) or solar panel captures energy from the sun and converts it into a DC electrical current. The silicon cells within these devices make it possible because of how they react to the sunlight and heat. The next step is to get the solar panel output it produces to your battery in a form that you can use in your RV.
The solar charge controller then acts as a go-between for the solar panels and your battery or battery bank. It handles both the current and the voltage going to your batteries to ensure they don’t get overcharged by keeping it at an optimal level. It can help prevent reverse charging or a short circuit, along with other safety protections to prevent damage to the system.
Overall, a solar charge controller will protect your battery and prolong its life. It can also boost its performance and efficiency too. It will make sure that the panels and battery play nice together despite the differences in their voltages. Some products work with only a 12-volt battery, whereas others will handle units with 24 or even 48 volts.
The inverter is essential if you’re going to use your solar setup to run AC appliances or devices. It will convert the DC current to AC current. You find both central and micro-inverters that control the entire array or just a single panel, respectively. The latter allows you to fine-tune your solar system to get the most out of the energy each of your solar panels is providing.
Now that you understand the purpose of a solar charge controller let’s move on to what you need to know when shopping for one. The first step is to determine how you’ll use your solar kit and how much input voltage and type of current you’ll need to run it, whether you’re using it for an RV or an off-grid system for your home. Many models are suitable for many uses.
You’ll find products that range from under $25 to models well north of $100. A higher-priced item isn’t necessarily the best choice, either. Several factors can affect the suitability of one item over another. The cost is only one part of the equation. Things to consider when shopping for a solar charge controller include:
If you rely on solar power when camping, you must consider how and when you travel to help you pick the right one for you. It will also come into play with the type and capacity of your system. The goal is to make sure you’re getting enough power to balance your usage with what your solar panel can deliver, based on its input voltage and battery voltage.
With RVing, you’re not selling electricity back to the utility company since you’re well, off the grid or boondocking. You may only need DC current or AC current if you have these kinds of appliances. You may find that you need a maximum power point tracking or MPPT charge controller, depending on the type of electronics you run. The bottom line is the voltage you need for your system.
Your home may be a different story if you’re on a grid-connected system. For the latter, you’re probably not using batteries at all. For the purpose of this article, we’ll stick with scenarios where you must store electricity with a battery bank of multiple batteries of a suitable voltage to ensure reliable power, whether it is a PWM or MPPT charge controller.
The essential consideration here is that you’re getting enough power when you need it without taxing your system or under-delivering. It’s all about balance. Bear in mind that you shouldn’t discharge lead-acid batteries more than 50 percent to prolong their life. A good place to start is by knowing your daily energy usage to determine whether you need a PWM or MPPT charge controller.
If you’re using light in an outbuilding such as a chicken coop, you get an estimate of the kWh and thus, get a better idea of what you need. For example, if you have a light on for 16 hours a day using a 100-watt incandescent bulb, you’re using in the ballpark of 1.60 kWh a day for that one device. As an aside, the same scenario with an LED would reduce it to 0.40 kWh.
If you run an RV solar kit with a 100-watt solar panel, you’re getting about 30 amps a day to run everything. Going back to our chicken coop example, you’re talking about 8.3 amps per day for the incandescent bulb, assuming you have a 12-volt battery. (Amps equals watts divided by voltage.) Doing the math, therefore, is a vital step no matter if you get an MPPT or PWM device.
These figures give you an idea of what you’ll need to run your system and in turn, help you select the right solar charge controller for RV or whatever setup you have. However, it’s important to remember that a 100-watt solar panel is consistently providing that amount of power or voltage. That’s only a best-case scenario for even an MPPT charge controller.
And we know how few and far between those things are.
Let’s put some numbers in perspective solar charger control, no matter if you get an MPPT or PWM device. The first one is the amps of your solar charge controller. That gives you an indication of its output and what battery you’ll need for your system. The idea is to balance it with what your solar panels are delivering. It’ll also influence other choices and features that we’ll cover later.
We’ll stick with our 100-watt solar panel with its accompanying 12-volt, deep-cycle, lead-acid battery, for now. The ideal scenario is that your solar charge controller will have a capacity that is at least 25 percent more than what your solar panels are delivering to your batteries. That gives you the option to expand your system down the road with minimal additional purchases.
You should avoid the other side of the spectrum where your solar panel is producing more than your charge controller can manage. At that point, it’s wasted energy. Not good. It defeats the purpose of going solar in the first place. Remember that extraneous, sometimes uncontrollable factors are part of the mix. They include things like cloud cover, aspect, and even the cleanliness of your solar panels.
All can affect the output of the PV array and its delivery to your battery bank with your PWM or MPPT charge controller.
Another spec you may see is the IP rating. This two-digit figure gives you an indication of how well a solar charge controller can handle the elements. The first digit denotes protection against solid materials like dust, sand, and other debris. It goes from 0 with no protection to 6 with maximum. The second number concerns moisture. It runs from 0 to 8, with the highest number for submersion.
A unit that is waterproof and dustproof will have a rating of 67 or higher. However, not only products will have this spec. Many devices aren’t meant for outdoor use. You’ll usually see this information provided in the description. Its value depends on your application. If you need to set up your solar kit outside, it’s imperative to get an appropriately rated model. If not, it certainly is not in the deal-breaker category.
Weather-resistant is not the same thing as waterproof. The IP rating is your best guide to what the solar charge controller can handle and whether or not you need to install it inside or in a protected spot. We think that this feature is imperative if you invest in a more expensive MPPT device.
There are two primary types of solar controllers, each with their pros and cons, read: price point.
The pulse width modulation (PWM) models are the less expensive of the two, being a first-generation product. Its function is to prevent your battery from overcharging, which it does well, albeit, not the most efficiently.
It’s essential to understand that solar power or any type for that matter has some inefficiency. It’s the nature of the game. The problem with solar is that we’re talking less than 20 percent. That’s one reason why we have given ranges on the different specs to make up for losses where you can. You can also make other changes to lower your draw, such as the LED lights we referenced earlier.
The other kind is the maximum power point tracking (MPPT) controller. This MPPT type is the better of the two because there is no loss of energy if you have a string of bright sunny days, topping off your batteries. A PWM doesn’t use the extra juice. When your battery is charged, it’s done and anything else isn’t stored.
The MPPT, on the other, hangs onto it at a lower voltage to keep your battery at full capacity because of its maximum power power tracking technology for managing voltage.
The MPPT is also a smarter choice between a pulse width modulation or power point tracking MPPT if you do winter camping because of this boost in its efficiency. Your batteries will discharge faster at colder temps for which this type can help compensate, no matter what the voltage.
The maximum power point tracking (MPPT) controller is also a smarter option if you have a larger setup with more solar panels or batteries with a higher battery voltage than the standard 12-volt charge. MPPT is the best choice for managing your voltage and input.
Many controllers can increase your efficiency significantly, making them worth the higher cost upfront. However, MPPT units can cost two, three, or even more times the price of a PWM model. We suggest keeping what you pay for a solar charge controller in line with the investment you have on the other components in your system to determine if an MPPT charge controller is right for you.
Of course, these options only scratch the surface about what’s available with solar charge controllers for managing your usage and voltage. Whether they fall into the dealbreaker or dealmaker category depends on your usage and application. We’ll touch on a few that are nice-to-have and others that are must-haves so that you can decide for yourself what matters.
Like charge controllers, batteries aren’t created equal, whether you have a sealed gel, AGM, or another type of battery. An adjustable charging voltage setpoint lets you match the output of your solar panels and solar charge controller with the kind that you have. You should also check the compatibility, especially if you have something other than a 12-volt battery.
An on-off switch allows you to power the controller down with disconnecting the system. Now that is convenient. You may also see products with a load control toggle or even a timer. The latter is desirable if you’re using your solar kit to manage outdoor lighting or motion sensors for pest control.
Likewise, a shore power option is another handy feature if you want to put your kit in standby mode if you dry camp. It’s also nice to have if you want to store your RV and maintain the health of your battery when not in use and still have your PV array connected.
Many solar charge controllers also provide information on the status of your battery and its voltage on an LCD screen. It may include things like a battery temperature sensor. Extreme heat, after all, is just as harmful to your batteries as freezing conditions. Many have a temperature compensation feature for additional protection against the elements.
Other products take it to the next level with information about the status of your solar panels and their output. Some use these data with a float charge feature that can help increase the efficiency of your system and ensure reliable power and safe battery temperature. Essentially, it acts as a trickle charge to prevent overcharging and prolonging battery life.
Of course, solar charge controllers are not without their bells and whistles that add to their value and usefulness. We’ve seen products with Bluetooth connectivity, USB ports, remote power management, data logging, and a slew of safety features like reverse polarity protection and negative grounding. Most products are easy to install with a compatible system to make the most of solar energy.
The best solar charge controller in our lineup is the Morningstar SS-10L-12V Sunsaver. It ticks off a lot of the boxes we like to see in these products for reliability, safety features like reverse polarity protection, and durability. It is also a versatile product, thanks to its outstanding construction and its full suite of safety protections when using solar energy.
Whatever your solar kit setup, you’ll find a product that will mesh well with your usage and power needs, whether you have a sealed gel battery or a lithium-ion one. As we’ve learned, technology is moving rapidly to close any gaps in affordability or features, especially with the best MPPT controller and safeguards like a temperature sensor.. The time to go solar has never been better for you and the environment.
Ross Spark is devoted to propelling the use of solar-based and solar oriented systems around the world. Believing that expanding access to this perfect, rich, clean, and economical energy source will greatly impact our well being and our future generations well being.