WHAT IS A SOLAR CHARGE CONTROLLER?
The solar charge controller is an electronic device that regulates the incoming electrical voltage from the MODULES before passing it to the batteries and The battery is subject to the electrical load in order to preserve the used batteries and to ensure that they are charged and used Optimally.
1.FUNCTIONS OF THE SOLAR CHARGE CONTROLLER
- Regulate charging of batteries (in order to preserve the life of the batteries), ie allowing a full charge without access To the case of overcharging.
For example, when using Lead Acid Gel batteries, it is known that at a voltage of 12.85 volts, this means
The battery reaches 100% charge, so the regulator does the following:
- Fast charging process until reaching a voltage of 12.60 V (75% charge).
- Then, the charging speed gradually decreases, regardless of the current produced from the module until the arrival Of 12.85V (full charge), then the charging process stops completely.
- The output current is separated from the module
- Regulate the electrical voltage coming from the module before it reaches the batteries
For example, it is known that the standard module’s power is 250-265 watts, and the open-circuit voltage is Voc = 37.5 Connecting two modules in a row, the output voltage of the two modules becomes 75 volts, and charging is required 48-volt battery set (consisting of 4 batteries connected in series 12-volt battery), then
The charge regulator reduces the voltage to charge the batteries from 75 to 51 volts. This is the primary function of the regulator which is Lead to battery preservation
- Charge level display
- Display of incidents (overload, deep discharge, short circuit)
2.CARACTERISTIC OF A SOLAR CHARGE CONTROLER
To choose a solar charge controller, you have to consider three main elements :
- Overload protection
- Protection against deep discharge
- Short-circuit protection
- Protection of photovoltaic solar panels (against charge returns electric)
- Thermal protection
- – Room temperature compensation to measure the battery charge
- – Wired or remote connection to a PC or computer network
- Triggering of automatically programmed alarms (audible signal, e-mail, SMS)
- -Recording for analysis of data from the regulator etc …
- The maximum open-circuit voltage of the panels: The regulators accept more or less wide voltage ranges.
- The minimum voltage to charge the batteries.
- the maximum intensity of the regulator: the intensity of the regulator (expressed in amps) must be greater than the short circuit intensity of the solar panels to which it is connected.
3. TYPES OF SOLAR CHARGE CONTROLLERS
I.Pulse-width modulation PWM
This type of controller sends the electric current to the battery in the form of electrical pulses and then adjusts it according to the size of the electrical current stored in the battery. The problem with this type is that it reduces the voltage and Keeps the same current value.
II.Maximum Power Point Tracking MPPT
The label refers to the mode of operation of the controller, is to track the point of maximum power, which are electric current transformers DC / DC passes electric current in the form of pulses like PWM type, but it has the advantage of being able to Optimum utilization of the electric current produced by the module because it reduces the voltage while increasing the charging current. Figure (1) illustrates the MPPT charge controller circuit.
THE MAXIMUM POWER POINT
It is known with an algorithm built into the charge controller used to extract the maximum available power from the module under certain conditions. The position of voltage at which the module produces the maximum power is called the maximum point Power () or peak power voltage).
The maximum power varies depending on the intensity of solar radiation and the ambient temperature
And solar cell temperature. Figure (2) shows the change of the point of maximum power with the intensity of solar radiation.
A typical solar module produces power with a maximum voltage of about 17 volts when measured at 25 ° C
, and it can go down to about 15 volts on a very hot day, and it can go up too To 18 volts on a very cold day
That is, the MPPT is a DC / DC inverter that works by taking DC input from the solar module.
And converting it to AC and then converting it back to a different DC current and voltage to match the module to the battery.
HOW THE MPPT WORK ?
The main principle of MPPT’s work is to extract the maximum available power from the solar module by making it operate at the most efficient voltage (the maximum power point).
This means that MPPT checks the output of the PV module, compares it to the battery voltage, and then makes sure of what best capacity the PV module can produce to charge the battery and convert To the best voltage to get the maximum current from the battery. And it can also supply DC load, which is connected directly to the battery.
THE MOST EFFECTIVE CONDITIONS FOR MPPT TO WORK
- Cold Weather: Typically, modules do best in colder temperatures and MPPT is used To extract the maximum available capacity from them.
- When the battery is deeply discharged: MPPT can extract more current and charge the battery in case when the battery charging is low.
MAIN FEATURES OF MPPT SOLAR CHARGE CONTROLLER
- In applications where PV cells are the source of electrical power, a maximum power point tracking regulator is used To correct the change in the current-voltage characteristics of the solar cell with the Iv curve.
- A Maximum Power Point Tracking (MPPT) charge controller is essential for any solar energy systems that need to have a power point tracking system The maximum capacity of the solar cell. Because it forces cells to operate at a voltage near the maximum power, Thus, the maximum available capacity can be withdrawn.
- The MPPT solar charge controller allows users to use solar modules at the highest voltage output which is greater Than the battery system operating voltage. For example, if the position of the solar module is further from the chare controller And the battery, then the size of the connecting wire is too large to reduce the voltage drop.
- MPPT controller reduces system complexity while the system output is highly efficient. in addition to It can be applied in combination with other energy sources. So the PV Module output capacity is used for control Direct in DC-DC inverter.
- MPPT regulator can be applied with other renewable energy sources such as small water turbines, turbines Wind turbines, etc.
The charge controller must be chosen according to the current delivered by the solar panels and the voltage of the battery bank:
THE MPPT & PWM WHAT ARE THE DIFFERENCES?
- For a PWM charge controller, the regulator must be able to operate on the battery bank voltage; the regulator current must be at least 1.5 times the short-circuit current of the solar panels;
- For an MPPT charge controller, the regulator must be able to operate on the battery bank voltage; the power of the solar panels must be less than or equal to the power acceptable by the charge controller; the voltages Voc and Vmp of the solar panels must be lower than the voltages acceptable by the charge regulator;
A new generation of regulators has appeared: MPPT solar regulators (for Maximum Power Point Tracking), which means finding the PowerPoint maximum). This new technology makes it possible to obtain the best performance from photovoltaic solar panels, from 10% to 25% more energy. An MPPT solar regulator has a scanning function, which traverses the voltage of the solar panel every two hours to find the power outlet maximum: thus it can adapt the voltage delivered by the panel to that which the solar batteries can absorb. These regulators not only increase the energy production of a photovoltaic installation but by optimizing the battery charge, they also significantly extend the life of these batteries. The MPPT charge controller, more expensive than these PWM colleagues, will be able to modify the module voltage and supply the voltage needed to charge at 100% of batteries.
III.Built-In Charge controller
The charge controller integrated with the inverter is programmed to prioritize the electrical load before charging the batteries ‘Solar Priority )This feature has major and important advantages over a separate charge controller from the inverter, Where the following is noted:
- In the case of a separate charge controller, the controller charges all the power coming from the modules in the battery, regardless Of the instantaneous electrical loads, then the inverter gets all the required power from the batteries as well. This method leads to continuous cycles of charging and discharging the batteries even during the day, thus shortening them In the life of the battery, if its life is, for example, 2000 cycles in the gel type, it consumes 4- 2 cycles per hour each day.
- When using the (Solar Priority) feature in the built-in controller, the inverter meets the needs Loads of electricity from the modules first, without going through the batteries, and the batteries are used only when there is an energy deficit. This method extends the battery life as the discharge process is only performed during Night and batteries are not going dead in continuous cycles of charging and discharging day and night without the need for this operation and converting electrical energy into chemical energy inside the battery and converting it back to electrical energy, causing an electricity loss of up to 30%, And if using a Built-in controller and runs on the (Solar Priority) system, this daytime waste is largely avoided, as The electric power (DC) produced by modules is transformed into (AC) power directly, and the charging process is limited. In the end, the Charging process of Batteries are limited to the surplus produced by Modules and this capacity is consumed only at night.
4 BEST SOLAR CHARGE CONTROLLERS
|EPEVER||MPPT||12/24/36||200 V||80 A|
- Type: MPPT
- Battery voltage: 12-24V
- Max input voltage: 200V
- Max current output: 80A
- Extra features: Four stage battery charging, temperature compensation, LCD screen, PC software, supports remote meter and multiple load control methods.
- The high points: A cheap MPPT controller compared to other top-tier models with great safety protections.
- The low points: Doesn’t offer as high of a max input voltage or max current output as other MPPT models.
- Mark C:I like that it’s programmable for lead-acid and LFP battery charge algorithms. It works well, I really like that I get 40% more amperage just moving from PWM to MPPT.
- Joe D..:Love fast response to shade,no interface needed with user features let’s you set your own voltage limits,looks very nice with battery temp monitor and remote meter thanks epever and Amazon got it quickly and in mint condition.
- Jerry Glisson:Best thing I have bought works like a champ.
- Type: MPPT
- Battery voltage: 12-48V
- Max input voltage: 150V
- Max current output: 100A
- Extra features: Bluetooth connection, remote management portal, battery monitor compatible.
- The high points: The advanced technology and intelligent management system make it perfect for RVs.
- The low points: Requires an additional purchase for full battery monitoring.
- Anytime anywhere remotely control and monitor the extensive features of your SmartSolar MPPT charger with built-in Bluetooth by pairing it with your smartphone or other device via VictronConnect
- Paul I.Victron components are incredible. I already had the BMV-712, and just added the SmartSolar 100/50 to add solar power to my RV. Used with two 100w Renogy mono panels, with the plans to add two more soon. The build quality of this solar controller is incredible, it feels like you’re getting what you’re paying for. As soon as I connected the solar panels, the unit powered on, even though I hadn’t connected the battery yet. This surprised me a little, I figured it would only be powered from the battery side, but if it does get enough power from the panels it will continue to run even if the battery is disconnected or the battery-side fuse is blown. So you’ll want either fuses or breakers on both sides so that you can power it off completely if you need to.
- crossed3:Excellent choice great app to check Motorhome electrics works well in conjunction with 3000w inverter goes back to bulk input after use of an inverter.
#3. Renogy Wanderer
- Type: PWM
- Battery voltage: 12V
- Max input voltage: 25V
- Max current output: 30A
- Extra features: Four stage charging, temperature compensation, LED indicators and protection against overcharging, overload, short-circuit and reverse polarity.
- The high points: Offers different ways of determining when the load is powered.
- The low points: The device is only equipped with an LED indicator light and doesn’t have an LCD display for important diagnostic data.
- Briggy:If you are looking for all the trimmings or running a large household grid tie array, this is not the controller for you. If you are looking to automatically light up the barn on all sides, you will adore this. For small solar power needs, such as rv, cabin, camping, and other plain deployments, this will simply do. In a word, I would peg this controller as “perfectly adequate”.
- Jeremy Brooks :Installed easily with a single 100 watt panel as part of the van setup.
- Simon G.:Using this controller with 2x 100W panel of the same company. It’s been in my RV for one year now. It doesn’t have any advance options on it but that’s what I like about it. I just installed it near my battery in a cabinet and forget about it.
It does a good job for charging my two RV batteries. I even didn’t removed my battery over the winter and it keept them just at the right charge.
I don’t use the temperature sensor yet, but I just bought it couple weeks ago and it should make it event better.
We use our setup just to spend 3-5 days off the grid and increase the number of place we can go camping. If you are not an hardcore off the grid person, this charge controller is perfect for you and not too expensive.
- Type: PWM
- Battery voltage: 12-24V
- Max input voltage: 24V
- Max current output: 20A
- Extra features: Auto shut-off, safety protections, moisture coating, LCD screen display, USB ports.
- The high points: Can use it with both 12V and 24V systems, including charging phones directly.
- The low points: Cannot connect it to more than 20A of load with the terminals.
- jmbillet :We are new to solar and got this for out camper. My husband has installed it and said that it works as it should. He is still learning the ins and outs of the solar, like voltage/wattage stuff. Very pleased with this purchase.
- Elvan :We have been full time RV living for just over a year now, traveling North America and seeing all the wonderful wild places we can get to in our 5th wheel RV. Until a month ago, we primarily relied on our 3400 watt generator to keep our batteries charged and our lights on. Early on I had considered getting one of these solar suitcases, but had the intention of adding a complete solar package to the RV during our second winter and initially decided to just deal with using the generator until then.Well, after a long summer of dry camping in remote locations, I quickly grew tired of starting the generator just to charge our batteries. So, we decided to have another look at a solar suitcase setup. I found a few cheaper varieties, but settled on the Renogy 100 Watt 12 Volt Monocrystalline Foldable Portable Solar Suitcase with a Voyager Waterproof Charge Controller.At this point I really wish we would have bought one of these up front. The first time we hooked it up to our very dead batteries, it took about three days to bring them to a full status. However, since then, we have been camping for weeks on end, using our phones, lights, fans and all the other typical 12 volt systems you might find in an RV, and this solar suitcase has kept our batteries topped off to the point that we only need generator power for high power items like the hairdryer, microwave and instantpot, etc…