Our ultimate guide on solar charge controllers will help you make the best decision on the right product for your solar panel system. These are some of the best solar charge controllers to buy on the market.
8 Best Solar Charge Controllers: What Product is Best?
When thinking of off-grid systems, apart from the solar panels, energy storage comes to mind.
Batteries are directly linked to off-grid systems, and batteries will need a charge controller.
Even though your batteries will indeed need a charge controller, these will not be always necessary. Such is the case of grid-tied systems or low capacity panels, like from 1 to 5 watts.
If that is your case, rest assured you won’t necessarily have to include a solar charge controller in your system,
If you need a reminder of how solar works, the image below will refresh your memory.
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What are Solar Charge Controllers?
In PV systems, solar charge controllers have the task of regulating and managing the charging process of your battery bank. In this manner, they protect your batteries.
They especially avoid reverse current and keep your batteries from overcharging.
Within the solar PV system they:
- Disconnect the panels once the sun goes down and the panels lower their energy production. This ensures your batteries will not discharge overnight.
- Prevent overcharging your batteries, which otherwise would cause premature aging.
- Control the rate and the voltage at which the battery charges, depending on how full the battery is.
How Solar Charge Controllers Work
Most of today’s charge controllers, work by allowing current to flow through the battery in different stages, depending on the battery’s charge level.
For instance, 4-stage charge controllers work in the following way:
When the battery is empty, the controller will charge the batteries at full flow.
As the battery gets charged and reaches the regulation voltage, the controller slows down the current flow to safe levels.
Once the battery is full, you will only have a trickle charge at low voltage to keep the battery topped off without overheating it.
Done only with flooded batteries, and it consists of periodic high voltage charge boosts to “shake-up” the electrolytes in the batteries, smooth the voltage of the cells and complete the chemical reactions inside.
Things to Consider When Buying a Charge Controller
When choosing the best solar charge controller for your system, there are a few things to keep in mind to ensure you pick the right one.
1. The Type of Solar Charge Controller
Choosing the best solar charge controller starts by picking the correct type for your application.
There are two main types to select from in solar PV applications.
Pulse Width Modulated (PWM) solar charge controllers
They work by slowly reducing the power flowing into the battery as it comes closer to the full.
Once that happens, they maintain a “trickle” state, i.e. supplying a small and constant amount of power to keep the battery at its maximum.
- This type works with the same voltage in as out, so the nominal voltage of your battery bank must match that of your solar panel system.
- Recommended to use in small DIY solar systems with a couple of low voltage panels and a small battery.
- Work great between 45 °C – 75 °C, and have good durability. Most have passive heat sink cooling.
Maximum Power Point Tracking (MPPT) solar charge controllers
MPPT charge controllers are more expensive and sophisticated than PWM.
They work by adjusting their input to extract the maximum power possible from your solar system. They can also vary their output power to match that of the battery.
MPPT provide the same protection as a PWM, and will also reduce the inflowing power to your battery bank as it comes close to capacity.
- Not cost-effective for homes or applications with lower solar power needs.
- Recommended for larger arrays.
- MPPT charge controllers can work with non-matching voltages from panels and batteries.
- More efficient than PWM, being able to provide up to 30% better performance than other controller types.
- Their complexity implies that they need to be installed and configured by expert hands.
- Able to harvest energy below 45 °C or above 75°C.
2. Maximum Voltage and Current
The controller’s capacity tells you how much voltage and current it can handle.
Max voltage ranges from 12 V for the smallest controllers to as high as 150 V for the most powerful devices.
Maximum input current oscillates from as low as 8A for RV and truck charge controllers to 80 A for high capacity ones.
3. Battery compatibility
Most controllers can be connected to 12 V or 24 V batteries, some only to 12 V ones, whereas others can charge batteries of up to 60 V.
Also, check the battery type. Most PWM’s are only compatible with lead-acid batteries, like gel, sealed and flooded. MPPT’s can support these types as well as lithium ones.
Lately, they are added more flexibility with the battery type they can work with.
4. Load Control
Solar charge controllers can turn the output load off automatically if the battery gets too low. This prevents extreme discharging.
If you want to be able to turn the load off at any time, look for a charge controller with manual load control. This is a switch or button you can press or toggle.
5. Temperature compensation
This feature is especially useful in hot areas.
This function ensures that the controller will reduce the voltage if a rise in the battery temperature is detected. This feature involves an external temperature sensor that will most likely come with the controller, or you can buy separately.
6. System monitoring and control
One of the most desired features of a charge controller is being able to monitor and control your solar system.
This characteristic allows you to check the status of your battery, how much power is being produced by the panel and other performance data.
Most solar charge controllers come with a simple LCD that shows you basic details. You can also configure certain parameters.
For easier monitoring, ensure that your device comes with a remote meter or it is compatible with one.
8 Best Solar Charge Controllers to Buy
With all this info already in mind, let’s move on to the best solar charge controllers out in the market.
Summary Table of Our Favorite Picks
Here is a summary of our top 3 picks for solar charge controllers to buy with descriptions and reviews.
Want to explore other options? Here is a description and writeup of each product that made our top sellers list.
This bright colored Solar Charge Controller will protect your battery against reverse discharge, over and under voltages with its intelligent PWM charging mode.
It is waterproof, dual-bottom designed, easy to set-up and features a large LCD to show you all the system necessary information.
It supports light and time control and it brings a dual USB port 5V – 3A output.
- System voltage 12 V / 24 V automatic identification
- 3 kinds of charge control: directly charge, boost charge, floating charge.
- Only applicable to various lead-acid batteries. Not suitable to use with lithium batteries, nickel-metal hydride batteries, or other elements.
- Intended for solar PV panel as charging source only. Not recommended to use a DC or other power source as a charging source.
This waterproof world-class quality charge controller comes with a blue backlit LCD that displays system information and error codes.
Being the first waterproof PWM charge controller in the market makes it perfect for outdoors and applications in which water splashes or rain are a common thing.
The Voyager has you covered with multiple solar panel, battery and controller protections.
- Suitable for 12 V off-grid applications
- 5 Stage PWM charging: Soft-Start, Bulk, Absorption. Float, and Equalization
- Compatible with 4 different types of batteries: Sealed/AGM, Gel, Flooded and Lithium Batteries with Lithium awakening feature.
- Watertight design with Backlit LCS display for system and error information.
- Multiple protection for batteries including reverse polarity and battery connection, reverse current from battery to solar panel protection at night, over-temperature, and over-voltage
Especially recommended for high-voltage battery banks, given its high voltage capacity of 150 V. It is perfect for large, off-grid systems.
The integrated Outback communications network allows the Flexmax charge controller to be remotely programmed and monitored via MATE system display. The MATE system also provides complete system integration.
Its intelligent thermal management enables it to operate at full maximum current rating of 80 A.
- It can handle an input of up to 5,000 Watts and a current of up to 80 A.
- Active cooling and intelligent thermal management cooling
- The advanced MPPT increases the output PV by up to 30% in all weather conditions.
- Flexible to work with most common types of lead-acid and lithium-ion batteries.
- Able to charge batteries from 12 V to 60 V DC.
- The built-in display with 80 character display shows data logs from the past 128 days.
- A bit pricey in comparison with other charge controllers
The Renogy Wanderer is a 30 A PWM solar charge controller that increases battery life and improves system performance thanks to its efficient PWM charging mode.
The multiple LED indicators notify users of charge status and battery information.
An included RS232 port allows users to communicate with the Renogy BT-1 Bluetooth module. This enables you to monitor and adjust your solar system remotely via the Renogy BT-1 smartphone app.
It also integrates a Lithium Battery Mode, which makes it capable of charging various 12 V battery types and banks, including most 12 V lithium models on the market.
- Optimized for a 12 V system; Deep cycle Sealed, Gel, Flooded, and Lithium battery option ready.
- Smart 4 Stage PWM charging and temperature compensation to increase battery life and improve system performance.
- Intelligent protection against reverse polarity, overcharging, short circuit, and reverse current.
With a built-in Bluetooth module, the Victron SmartSolar MPPT allows you to check your battery or power flow status right on your smart device.
It also enables you to use it through an internet connection via the Victron Remote Management Portal, which is great for setting up, updating and monitoring remote systems, like those in RV’s.
The free app enables you to set the battery charge algorithm, the timings, and light deeming options. It also shows battery voltage, current, and actual charging stage.
It comes with three indicators that show the current state but no LCD screen at all. The monitoring is done via the internet or smartphone app.
It does not come with an external battery temperature sensor, nor it seems to be available anywhere.
- Ultra-fast Maximum Power Point Tracking.
- Advanced Maximum Power Point Detection in case of partial shading.
- Compatible with Gel, Flooded, AGM, Lithium-ion and LiFePO4 batteries.
- Natural convection cooling.
- Automatic battery voltage recognition.
- Flexible charge algorithm.
- Temperature compensation feature to protect your batteries from overcharging or overheating.
This cost-effective MPPT charge controller is a high-quality product with a high tracking efficiency of no less than 99.5% and a peak conversion efficiency of 98%.
The Epever 40 A MPPT solar charge controller has been designed to optimize your battery’s life and improve the overall system performance.
It shows ultra-fast tracking speed with its advanced MPPT control algorithm to minimize the maximum power loss rate and loss time.
- It works in a 4-stage charge modality and includes the temperature compensation feature.
- Protects against reverse polarity, overcharging, over-discharging, overload, short-circuiting and reverse current.
- It performs system voltage identification 12V / 24V automatically.
- Compatible with several deep cycle battery options: Sealed, Gel, Flooded, and Lithium.
- Advanced MPPT Wide MPP operating voltage range
- Real-time energy statistics function
- Multiple load work modes
The Renogy Rover series of MPPT charge controllers provides you with efficient charging for 12 V or 24 V off-grid solar systems.
This solar charge controller uses a powerful smart tracking technology to maximize the solar charging process to your battery.
Also, the Rover Elite MPPT integrates multiple battery, controller, and solar protections to assure you peace of mind and an optimized and reliable system.
The package includes the Rover 20 A MPPT charge controller and a temperature sensor.
- 12V /24V Automatic System Recognition.
- Backlit LCD system information and identifying error codes.
- Advanced MPPT Technology with up to 99% high tracking efficiency, 96% conversion efficiency, and Lithium-reawakening feature.
- 4 Deep Cycle Battery Pre-Sets: Gel, Flooded, Lithium-Iron Phosphate (12.8V), and Sealed/AGM.
- Multiple Electronic Protection Features, including overcharging, over-discharging, reverse polarity, over-load, and over-temperature.
Intelligent and multifunctional, this solar charge controller comes with an LCD screen to make interface operations easier to carry.
The integrated light-control connects and disconnects the panels according to the time of the day. Once the sun goes up, the light source will turn off, and the solar panels will start charging the batteries.
Every single controlling parameter can be customized to satisfy particular user needs.
- Offers overcharge, over-discharge, overload protection, and reverse connection protection, as well as short circuit protection.
- Easy to read and use LCD screen.
- Applications range from dual batteries to boats, RV’s, Trailers and Caravans. (see these best boat solar panels)
- The integrated 5V 1A USB port output allows you to charge your mobile devices directly.
- Automatic 12 V / 24 V system recognition.
- With the temperature compensation feature, charging parameters can be automatically adjusted.
Need solar panels? Use our guide to the best solar panels to find the best option for you.
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