When building a solar power generation system, the connection of solar panels is the key part to determine how much voltage and current the system outputs. The three main methods of connecting multiple solar panels are series, parallel and combination of series and parallel. Let’s introduce them respectively below:
Series connection
When multiple solar panels are connected in series, the positive terminal of one solar panel needs to be connected to the negative terminal of the next solar panel, and so on. After the connection is completed, you will get the voltage value of each solar panel, and the sum is the final voltage of the photovoltaic group. But the current readings do not add up, and the readings remain the same regardless of how many solar panels are connected in series.
For example, when two 12 volt solar panels are connected in series, the voltage can reach 24 volts, while the current remains a parameter of the current of the solar panel.
Parallel connection
In parallel, connect the positive or negative conductor of the solar panel to the positive or negative conductor of the next solar panel, and so on. The positive pole is connected to the positive pole, and the negative pole is connected to the negative pole, but the Y-branch connector is required for parallel connection.
In contrast to series connection, the voltage value of parallel connection is not added, and no matter how many solar panels are connected in parallel, the voltage value remains unchanged, and the current value of each solar panel needs to be added.
For example, three 12 volt solar panels are connected in parallel, the voltage is maintained at 12 volts, and the current is 3×6 A = 18 A.
Series parallel combination
When you need to connect multiple solar panels in series and parallel, the order is generally series first and then parallel. In other words, first, form the same series group, and then connect the series groups in parallel.
It should be noted that solar panels of the same specification can be connected in series and parallel. If solar panels of different specifications are connected in series and parallel, it will lead to various problems such as voltage and current instability.
For example, four 12 volt solar panels are connected in series and finally connected in parallel to obtain a voltage of 2×12 volts = 24 volts and a current of 2×6 amps = 12 amps.
Fuse installation
We recommend installing a fuse between the positive terminal of the solar panel and the positive terminal on the charging controller. When you connect the solar panel in series/parallel / series-parallel mode, it is not necessary to install a fuse between each solar panel.
The choice of fuse size depends on the ampere value of the current, including how many solar panels you have combined together and how they are connected (Series/parallel / series-parallel), and then use the above calculation method to obtain the ampere value of the current of the solar photovoltaic group.
For example, if you have two 100 Watt Solar Panels in series, each generating 5 amps of current, the total output current is 5 amps. We usually set a safety value for the current, which is generally 1.25 times the current. Therefore, it is sufficient to select 6.25 a fuse or 10 a fuse for this photovoltaic group.
