With the popularization of solar power, more and more people are willing to buy photovoltaic panels and use solar energy as a new type of energy. We know that the solar panels are DC current output and the batteries are DC current input in energy storage solar systems, so you can’t help but wonder can I connect solar panels directly to battery? This section will tell you the answer and give you the solar panel connected to the battery diagram.
1. How to set up solar panels?
When you purchase the photovoltaic panels you need, you have to do two things:
The tools you need for installation: scaffolding, removal of the existing roof and other roofing works, internal wiring works, sorting out a connection agreement with the energy supplier, electrical connection work, and a generation meter.
Before installation, there is something you need to know about affecting solar panel efficiency 4 factors.
4 factors affecting the efficiency of solar panels:
1) Location, Angle, and Direction: To get more sunlight and the maximum efficiency, south-facing and 34° roof title angle is the best position according to Stanford University.
2) The size of solar panels: The solar panel system is proportional to your power needs. The more energy you need, the bigger the solar panels, the more electricity.
3) Roof suitability: When considering solar panels for your roof, whether the roof is strong enough to support the weight of the solar systems or if the roof is large enough to have solar panels on also need to access.
4) Maintenance: Solar panels maintenance is simple and the cost is almost free. What you can do yourself is ensure your panels are clean at all times.
Some areas don’t need to apply for permission for most domestic solar panel installations like In England, Scotland, and Wales. But in some cases, you need to do it first, for example, if your panels protrude more than 200mm from your roof.
2. How to connect solar panels?
It’s not difficult to connect the solar panels together. In general, there are three ways to connect, depending on your home's electricity requirements.
If you want to increase the total voltage for the whole solar system, you can use this type of connecting solar panels together in series. That is to say, their current is the same, and the total voltage is the sum of the output voltages of all the panels.
The total current: 3A
The total voltage: 12*3=36V
When three same panels are connected in series, their current doesn't change, but the total output voltage of the array is three times that of one panel as shown in series wiring.
As solar panels in series, if you want to increase the total current for the whole solar system, you can use this type of connecting solar panels together in parallel. That is to say, their output voltage is the same, and the total current is the sum of the output currents of all the panels.
The total current: 3*3=9A
The total voltage: 12V
When three same panels are connected in parallel, their voltage doesn't change, but the total output current of the array is three times that of one panel as shown in parallel wiring.
Combining the advantages of the above two connection methods, if you want to increase the total current and voltage for a solar system, you can use this type of connecting solar panels together in both series and parallel.
The total current: 3+3=6A
The total voltage: 6+6=12V
Please note that, if you want to connect in this way, you have to make sure that you meet the series wiring and parallel wiring conditions, which are the same current in series and the same voltage in parallel.
Maybe you will ask which wiring is the best way? In theory, it depends on your inverter you will use. And you'll find the answer to this page" Which wiring connection is better?".
3. Can I connect solar panels directly to battery?
If you want to connect the solar panels directly to a bank of batteries, it may work in theory.
But I don't recommend it for two reasons.
1） It may cause the battery to overcharge.
For example, when the photovoltaic panel output voltage must be the same as the battery voltage, it can be charged. A standard 12V solar panel that can be charged a 12V battery can produce an output voltage of more than 12V even 20V at full sun. In this case, the potential difference will be generated and more current will flow into the battery, resulting in the phenomenon of overcharging the battery and reducing the service life of the battery.
2）It may cause current backflow from the battery.
At night, there is almost no voltage and current generated by the photovoltaic panels. Then the battery will discharge and the current will flow back into the solar panels, causing waste energy.
Normally we connect a charge controller between the photovoltaic panels and the battery. However many home users have used solar inverters for the replacement of charge controller, which is more powerful than charge controller and easier to use. And I use luxpower solar inverter as a reference here. For detailed recommendations, please see” How to choose the best solar inverters for home?”.
4.How to connect solar panels to battery?
Solar panel connected to battery wiring diagram
The three wiring modes of the solar panels have been mentioned above. Next, according to the wiring diagram, we can see that the positive terminal of the PV panel is connected with the positive terminal of the inverter, and vice versa for negative terminals.
The battery is connected to the battery terminals of the inverter (same as PV panel wiring, the positive terminal of the battery is connected to the positive terminal of the charge inverter and vice versa for negative terminals).
The solar panels, batteries, and solar inverters have made up an energy storage system. During the day, the solar panels generate solar energy to supply the loads, and the battery is fully charged, and at night the battery is discharged to supply the loads. In this way, people can reduce long-term energy costs while minimizing their carbon footprint.
If you have any confusion, please contact us at firstname.lastname@example.org.
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