How To Use Solar Panels Directly Without Battery
If battery storage isnt in the cards for now, dont worry! You can use your solar panels directly without battery storage. Heres how it works:
Early morning and evening are times with lower solar production, but higher energy needs. Youre waking up and getting ready for the day, or making dinner and doing homework with the kids. Thats when youll need a lot of power, but also when solar panel production is just getting momentum or tapering off.
During these times solar owners without battery storage draw power from the grid, which acts as a giant energy backup system.
But during the day even when its cloudy your solar panels are likely providing more than enough energy to power your home. The excess energy is sent into the grid to power your local community.
Simply put, when the suns shining, you use your own solar power and send excess power to the grid when its not, you draw from the grid.
This kind of setup is called a grid-tied system. This could be considered a way to store energy without needing a battery system.
If you have your own battery storage, you likely wont transfer much energy to or from the grid. You store your own energy and pull from that, and the grid serves as a backup to the backup.
Do I Need A Charge Controller When Using Solar Panels
Solar charge controllers are an essential element to any solar electric panel system. Charge controllers prevent the batteries from being over charged and prevent the batteries from discharging through the solar panel. A charge controller is an electronic device that controls the flow of electricity from the battery to the inverter.
Charge controllers can be used in a variety of ways, but they are most commonly used to regulate the voltage of a battery. The voltage is regulated by a voltage regulator, which is a circuit that regulates the amount of current flowing through a device. In the case of solar panels, this is accomplished by controlling the charge on the panels.
A solar power system consists of two components: a solar array and a system to convert solar energy into electrical energy. Solar panels convert sunlight into electricity, and the system converts the electricity into heat. As a result, air molecules are attracted to each other, causing them to condense into droplets and form clouds.
Connect The Battery And The Controller
The second step is to link the 12-volt batterys cable to the charge controller. The solar charge controller is known for being a valuable component for averting overcharging. This component does a great job of interfacing the batteries and the solar panels. Hence, it helps regulate the solar energy from solar panel systems to batteries.
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Make The Battery Cables
I didnt have pre-made battery cables lying around. So I decided to save some money and make my own.
Turns out its pretty easy. Heres how I did it:
Cut two pieces of wire to the length you want and strip both ends.
Put the fuse in the fuse holder. Use our fuse size calculator to find the right fuse size.
Connect one of the fuse holders wire leads to your shorter battery cable with your wire connector of choice.
Shrink wrap the connector with heat shrink tubing and a heat gun.
Slide a piece of heat shrink tubing onto each battery cable .
Then crimp the battery terminal connectors onto the battery cables and shrink wrap the connections. Look at your battery terminals to know which size connectors to use. Mine uses 1/4 ring terminals.
Battery cables complete!
Now theyre ready to be connected.
Setup Stands For Inverter And Battery
Your residential solar unit is incomplete without stands for the battery and inverter. Again, you have the option of building the stands or getting them. Once the allocated positions for the inverter and battery are ready, you can start working on the wiring. Start with wiring the controller. The first connection from the left is for connecting the controller with the solar panels. The second connection is for pairing the battery with the controller. The last connection is for connecting the controller to the direct DC load connection.
For connecting the solar panel with the charge controller, you will need a separate connector called an MC4 connector. Once the controller is connected to the battery, its LED lights should light up. Similarly, you will have to connect the inverter terminal with the batterys terminal.
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Connect Your Solar Panels Solar Charge Controller And Battery Bank
Before you connect solar panels to batteries, you have to set up the charge controller first.
You have to connect positive to positive leads and negative to negative leads on the battery and solar charge controller. If you have more than one battery, make sure you connect the positive of your solar charge controller to one end of the battery and the negative to the opposite for a balance charging.
For you to hook up solar panels to your solar charge controller, connect your solar panels adapter kit first. After that, connect the panel and the controller positive to positive and negative to negative.
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The Correct Solar Panel Size For Charging The Rv Battery
The amount of solar power youll need to charge your RV battery will vary depending on several factors, including the battery size, the climate youre RVing in, and how much power youre using while camping.
That said, there are a few general tips we can give you when it comes to sizing your solar panel system for your RV.
Most RV batteries are 12V, but a 200W to 400W solar setup will be adequate even if you have a larger unit. Remember that all solar systems need plenty of sunlight to provide the maximum output. However, you may need a larger solar panel system if youre RVing in an area with less sun or using a lot of power while camping.
A 200W setup is enough for supplying electrical power for all basic electronics like lights, phones, and appliances that run with propane. However, its output wont be enough if you add power-hungry appliances like a microwave, air conditioner, and TV. In that case, you must use a 400W setup or something similar.
Finally, its important to remember that the amount of solar power you need to charge your RV battery will also vary depending on the type of battery you have. Lead acid batteries, for example, require more energy to charge than lithium-ion batteries.
So, how do you know what size solar panel system you need to charge your RV battery? The best way to find out is to consult with an expert or an RV dealer. They can help you determine the size of the solar panel system you need based on the abovementioned factors.
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Wiring The Battery To The Charge Controller
The thickness of the wire will depend on the type of charge controller you get. If you get a 20 amp charge controller, you need to use a wire thickness that can carry 20 amps without overheating . Flexible wires with a nylon coating are preferred . Learn how to select wires and thickness in my book.
You need to keep these wires as short as possible because they will be expensive.
When connecting the battery to the charge controller, you need to wire the black wire first, then the red to the charge controller. There might be a small spark but that is normal .
Gather Solar Power Components
It all begins with gathering the basic ingredients of a solar power unit. You will need four major items solar panels, charge controller, inverter, and a battery pack. In addition to these items, you will require a breaker, meter, MC4 connector, and fuses among other things. Keep in mind that it is essential to read the solar panel module instructions.
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Pwm Vs Mppt Charge Controller Test
We often get asked about the actual difference you get between an MPPT and a PWM controller so we setup a side by side test using our Yingli part used panels onto 2 separate 12V batteries, 1 with a PWM controller and one with our tracer MPPT. Panels were set-up side by side angled south.
With early March sun the MPPT was giving 3.7A into the batteries while the PWM gave 2.5A which was 32% lower than the MPPT.
In cloudy conditions the MPPT was giving 1A when the PWM was giving 0.8A
Both charged the batteries well, but 20%-32% more power was gained by using the MPPT.
Should I Connect My Solar Panels In Parallel Or Series
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- When solar panels are hooked up in series you connect the minus of one panel to the plus of the next panel.The voltages are summed, but the current remains the same:Putting panels in series is desirable as it keeps the amperage low, and amperage is the key factor in cost of the wire.Now lets look at panels in parallel. Here all the negatives are connected to each other, and all the positives are connected to each other. So the voltage stays constant and you sum the currents.With a PWM charge controller youll want to put the panels in parallel as those devices reduce the voltage to the batterys voltage and would otherwise waste a lot of power.When using an MPPT charge controller it will have a maximum voltage and current that you can put on any input. You typically put the most panels you can together in series but not so many you exceed the voltage. You repeat that for as many panels as you have and then connect the strings together in parallel.For example, if you had 6 panels with Vmpp= 22.5, Impp=5.75 and an MPPT with 60 volts and 20 amps max then you might arrange your panels into three parallel strings of 2 panels in series.When a panel in a series is affected by shade, it can reduce the voltage of the entire string, reducing the power output of the string.One way around this is to use diodes as shown below:Note that most modern solar charge controllers have blocking diodes built in to prevent draining your batteries at night.
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Can I Connect A Solar Panel Directly To A Battery
Yes, you can connect a solar panel directly to a battery. However, you will not be able to get the full power output of the solar panel if you do this.It is better to use a charge controller in between the solar panel and the battery. The charge controller regulates the flow of electricity and protects the battery from overcharging.
What Happens If You Connect Solar Panels Directly To A Battery
When sunlight hits the cells on a solar panel, it produces a chemical reaction and generates direct current . The solar panel transmits this current into the battery. The current is used to charge the battery and can also be used to run appliances and other devices.
If the solar panel is directly connected to the battery, all of the current is placed in the battery. A 12V battery needs only 12 volts, at most 14.4.V to charge. A 12V solar panel produces up to 20V.
If you put 20 volts in a 12 volt battery, it will overcharge. This is going to damage the battery and whatever device or appliance is connected to it.
By installing a charge controller like the Binen 20A Charge Controller , this can be avoided. You place the charge controller between the solar panels and the battery, and it will regulate the current flowing into the system.
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One Or More Batteries
Whether there are one or more auxiliary batteries, and whether they are installed in the vehicle, under the bonnet, in the passenger cabin, in the tray, in a trailer or in a caravan, does not effect the design arrangements outlined in this article. For the purpose of simplicity, this article will refer to only one auxiliary battery. A bank of batteries in parallel behaves the same as one large battery. Wherever you see second battery or auxiliary battery you can replace it with a bank of batteries. Batteries arranged in banks work best if they are matched, so that they have matched voltage profiles and charge / discharge at the same rates, but this is not absolutely necessary. All lead acid batteries behave fairly similarly. When connected in parallel, batteries do not need to be exactly matched, as charge and discharge current will naturally distribute between them according to their capacity. A larger battery or a battery with less internal resistance will sink more current when charging as it pulls down the charging voltage. That battery will supply more current under discharge as its voltage will not drop as much.
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Connect Charge Controller And Inverter To Battery Cables
The next step is to connect the charge controller and inverter to the battery cables. Before doing this, make sure that the charge controller isnt connected to the solar panel and the inverter is not turned on.
When connecting your solar panel to your charge controller, it is advisable to connect first the adapter kit of the panel. Then connect the positive or negative leads of the panel and match them to those of the charge controller. See to it that the panel is well inserted otherwise, you are likely to experience reverse polarity and a short to the system, which can damage the controllers and panels.
It is also important to note that a reliable charge controller will help to average the panels voltage fluctuations and give the batteries a steady charging voltage. It also comes in handy in preventing an overcharge of the batteries as well as protecting the panels from the risk of current back flow that comes from the batteries.
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Connecting Solar Panels Together Summary
Connecting solar panels together to form bigger arrays is not all that complicated. How many series or parallel strings of panels you make up per array depends on what amount of voltage and current you are aiming for. If you are designing a 12 volt battery charging system than parallel wiring is perfect. If you are looking at a higher voltage grid connected system, than youre probably going to want to go with a series or series-parallel combination depending on the number of solar panels you have.
But for a simple reference in regards to how to connect solar panels together in either parallel or series wiring configurations, just remember that parallel wiring = more amperes, and series wiring = more voltage, and with the right type and combination of solar panels you can power just about any electrical device you may have in your home.
For more information about Connecting Solar Panels Together in either series or parallel combinations, or to obtain more information about the different types of solar panels available, or to explore the advantages and disadvantages of using solar power in your home, then to order your copy from Amazon today and learn more about designing, wiring and installing off-grid photovoltaic solar electric systems in your home.
What Is A Charge Controller And Why Do I Need One
A charge controller is a device that regulates the current and voltage that goes to the battery. To understand this situation, picture a scenario where your solar panel is getting sufficient sunlight. Your 12V battery only needs around 13.6 volts from a 12V solar panel to get charged.
However, the output from your solar panel can range from 17 to 48 volts depending on the type. Can you see the problem here? If there is no charge controller to provide a regulated voltage to your battery, it will get overcharged and damage will occur. The charge controller also senses if the battery is full. When the battery is full, the charge controller will stop delivering energy to the battery.
This is why you cant connect your solar panel directly to your battery.
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Solar Panels In Parallel With Different Voltages And Currents
Here the parallel currents add up as before but the voltage adjusts to the lowest value, in this case 3 volts. Solar panels must have the same output voltage to be useful in parallel. If one panel has a higher voltage it will supply the load current to the degree that its output voltage drops to that of the lower voltage panel.
We can see that the solar panel rated at 9 volts, 5 amps, will only operate at a maximum voltage of 3 volts as its operation is being influenced by the smaller panel, reducing its efficiency and wasting money on the purchase of this higher power solar panel. Connecting solar panels in parallel with different voltage ratings is not recommended as the solar panel with the lowest rated voltage determines the voltage output of the whole array.
Then when connecting solar panels together in parallel it is important that they ALL have the same nominal voltage value, but it is not necessary that they have the same ampere value.
Connect Solar Panels To Charge Controller
The third and final step is to connect the solar panels to the charge controller.
If you have more than one panel and are unsure if you need to connect it in series or parallel, check out my article here or if you have two solar panels and one battery check out the wiring diagrams here.
Confused about the specifications of the solar panel you got? Check out my article, where I explain all the parameters of a solar panel here.
Use the cables that come with the solar panel, these are UV-resistant cables. Other cables will crack and break over time when they are exposed to UV radiation. This is the part when you need to oversize the diameter of the wire to account for voltage drop. Try to keep the voltage drop under 3%. to calculate the voltage drop.
What is voltage drop?
Voltage drop occurs when you have a long cable that delivers energy from point A to point B. The cables length increases the cables resistance, which will reduce the voltage at point B.
For example, your solar panel delivers 18 Volts DC and 5.8 amps to the charge controller and the wire length is 40 feet.
As you can see in the calculation, the voltage drop is 4.09%, reducing the overall power delivered to the charge controller.
Lets calculate the amount you will lose: 0.74 volts x 5.8 amps = 4.3 Watts.
This is not much, but this can add up quickly if you have multiple panels. In your country, it could be that the voltage drop may not be above 3% by law. To reduce the voltage drop, you use thicker wire.
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