MPPT Charge Controller for Solar Panels

40A MPPT Solar Charge Controller

MPPT Charge Controller for Solar Panels

Charge controller for off-grid solar power systems:
  mountain huts
  tool sheds
  alarms and video surveillance
  filtering and pumping water
  road signs
  ...and so on

During the sizing of a stand-alone solar power system (also called off-grid) some people spend thousands of euros to have the best performing batteries, without worrying about the choice of the charge controller, component on which the system safety and the battery bank lifetime depend.

During the sizing of a stand-alone solar power system, other people tend to spend more than necessary for solar panels, ignoring the huge difference in efficiency between traditional PWM controllers and modern MPPT controllers. In fact, not everyone knows that an MPPT solar charge controller is capable of extracting up to 30% more solar power than a PWM controller. Yes, exactly... 30%. At low temperatures, the difference increases even by 45%!

What does all this mean? It means that they often find themselves with an expensive, bulky and inefficient system. Let's take a practical example: let's take a classic 100W 36-cell panel. Well, under Standard Test Conditions (STC) a PWM controller will extract approximately 70W (100-30%) from our panel, while a high efficiency MPPT controller will use all the panel power (100W) to recharge the batteries and therefore that panel will be worth all the money spent and the space occupied.

This charge controller for solar panels uses MPPT technology and has a conversion efficiency between 95% and 98%. In addition to ensuring a greater transfer of solar power, it also offers a 4-phase management of the charging process thus increasing the lifetime of the batteries that we are going to connect.

solar charge controller for lithium lifepo4 batteries

What types of batteries can be managed and how to select them? As visible from the photo, the charge controller is equipped, on the left side of its terminal board, with a pair of white electric switches (called slide-style DIP switch) and a table of combinations. By positioning these two numbered switches, it will be possible to select four types of batteries and activate the best program that will manage their charge:

•   Lead-acid (Sealed)
•   Gel
•   AGM
•   the modern LiFePO4 batteries

The ease and rapidity of battery type selection represent another distinctive feature of this MPPT charge controller. You can connect both 12V and 24V batteries: the controller will automatically recognize their rated voltage and consequently set the right charging voltage. If you use 12V batteries, you can connect solar panels for an overall power of 480W while if you use 24V batteries, it will be accepted a maximum input power of 960W. Here is a guide on how to wire multiple solar panels in parallel to achieve these amounts of power.

What is the best battery type for an efficient solar power system? Today, the best batteries for solar storage are undoubtedly the LiFePO4 batteries (with dedicated BMS). They are light, safe and really last many years. They can also be fully discharged using all their capacity and be quickly charged with high currents. The perfect choice for our controller that can charge the batteries with currents up to 40A.

The same current is also guaranteed to power any electronic device connected to the LOAD terminals (the two terminals with the bulb symbol). The LOAD output is protected against overloads and short-circuits. The external casing of the MPPT charge controller is made of die-cast aluminum in order to guarantee the best ratio between strength, lightness and heat dissipation capacity. In addition, a fan for air circulation is mounted on its back.


40a mppt solar charge controller

A good 40A MPPT solar charge controller can't be supplied without some important accessories, right? Well, let's see what they are and their respective function within our system.

The first accessory is the remote digital meter. Thanks to its backlit display you will be able to easily view and monitor all the parameters in real time from a point of your choice (battery voltage, charging current, total power, battery capacity, energy). The meter comes with 4 fixing screws and a connection cable 5 meters long. In addition, the most tech-savvy users can monitor the progress of the charge even from their Smartphone or iPhone. The controller has in fact a bluetooth antenna and a dedicated app, free of charge, in 8 different languages.

Another important accessory that you will find in the package is the temperature sensor. Fixed on a 3 meter long cable, it must be connected to either one of the two poles of the battery. In this way the controller will also take into account the battery temperature during the entire charging process. Reading this information, often absent in the poorer controllers, is essential to guarantee the correct charging voltage. For connection, the inner diameter of the sensor eyelet is 8mm. Finally, you will also have an 80A blade fuse that will guarantee maximum protection against any short circuits along the line and then, of course, you will have the instruction booklet.

Wiring diagram

off-grid solar system wiring diagram

First, you need to set the type of battery that the charge controller will have to manage. To do this, just look at the table printed on the controller, find the technology of your battery and position the two switches accordingly. Then, the temperature sensor will be fixed on one of the two poles of the battery (or on the side of the battery, as you prefer) and its connector will be connected to the controller port called "Temp. Sensor".

Once we have done these two operations, we can connect the battery to the controller through a pair of cables with a section equal to or greater than 10mm² and less than two meters long. I advise you to choose a pair equipped with a fuse holder near the positive terminal of the battery so as to place the 80A fuse supplied. Fuse is optional but recommended because in the event of a short circuit on the line, the fuse will protect the cable from immediate overheating and from the risk of fire. The charge controller, on the other hand, already has internal protection against short circuits. We therefore connect the red cable from the positive pole of the battery (1) to the positive terminal of the controller (battery output) and then the black cable (2) to the negative terminal of the controller.

Excellent, at this point we can prepare to connect the solar panel. Let's cover the panel (or the string of panels) to avoid the formation of sparks during the wiring. After that, we can connect the panel through a cable with a section equal to or greater than 10mm² to the terminals "+" and "-" of the controller (solar input), paying attention to the polarity. Finally, we can take the DC load that we want to power, making sure that it respects the maximum allowable watts (480W at 12V, 960W at 24V) and that its power switch is in OFF position. Then we just have to connect our load to the LOAD output (numbers 5 and 6) and turn on the power switch. Congratulations, the solar power system is now complete!

Technical specifications

Maximum PV power •   480W (12V systems)
•   960W (24V systems)
Maximum PV voltage (Voc) 50V
Battery type •   Lead-acid
•   Gel
•   AGM
•   LiFePO4
Battery voltage •   12V
•   24V
Maximum battery current 40A
Self-consumption ≤ 4mA
Efficiency > 95%
Bluetooth YES (app in 8 languages)
External material Aluminum
Dimensions 147 x 155 x 40 mm
Weight 850 g


In compliance with European directive 1999/44/EC, the warranty is valid for 2 years on conformity defects from the issuing date of the sales receipt or invoice. If the product does not entirely meet your expectations, you have the right to return it within 14 days and get a full refund. No questions asked.


On average, delivery within the European Union takes 2 to 5 working days. If your delivery address is outside of the European Union, you may be subject to customs charges and delivery may take a few days more. Anyway, you will receive an email notification as soon as the product is shipped.

Payment methods

You can make the purchase using your Paypal account and the most popular credit cards such as Visa, Mastercard and American Express. Click on the "Add to cart" button and choose the method you prefer. If you have any questions about the product, do not hesitate to contact us.

Price:   235,00    

  Out of Stock

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mppt solar charge controller