Lead-acid, ternary lithium, lithium iron phosphate, who is the king of batteries?

1. What is the difference between series and parallel?

The series voltage increases and the parallel current increases, P=U*1

The total power of two 100W shingled solar panels connected in series is 200W, the open circuit voltage is doubled to 27.9*2=55.8V, and the current remains unchanged;

The total power after parallel connection is 200W, the open circuit voltage remains unchanged at 27.9V, and the current increases, the same is true for multiple solar panels connected in series/parallel.

2. What are the advantages and disadvantages of series and parallel connection?

Series connection: It can save the cost of wire materials, but once the solar panels are connected in series, once they are blocked, it will easily affect the overall power generation;

Parallel connection: The current is large, and the wire needs to be thicker, but after parallel connection, if one of them is damaged and loses its power generation capacity, forming an open circuit, it will not affect the entire circuit.

The solar panels on his branch are working fine.


3. When to connect in series or in parallel?

If there is an object on the roof that is likely to cause occlusion, such as an overhead air conditioner, or considering frequent shadow occlusion in the parking environment of the vehicle, it is recommended to connect them in parallel as much as possible under the conditions of MPPT and current upper limit. The stability of parallel connection is higher, and the circuit is not easy to be completely paralyzed. Although it will increase the cost of some wires, but it is not a long-distance transmission, so the increase of wires will not be much.

4. Can boards of different specifications be connected in series/parallel?

After series connection, the open circuit voltage should not exceed the maximum value of the controller at low temperature, but it is not recommended to connect solar panels of different specifications in series and parallel. Solar panels of different specifications are connected in series, and the current value of the entire circuit tends to the solar panel with the smallest current. In the same way, after parallel connection, the voltage value of the whole circuit tends to be the solar panel with the minimum voltage, which is a waste for the high-power solar panel in the same circuit.

Post time: Jan-06-2023